diff --git a/bindings/python/wscript b/bindings/python/wscript
index 5a5309575..4d2dcf516 100644
--- a/bindings/python/wscript
+++ b/bindings/python/wscript
@@ -1,17 +1,18 @@
 ## -*- Mode: python; py-indent-offset: 4; indent-tabs-mode: nil; coding: utf-8; -*-
 
 import re
-import Params
-import Configure
-import Object
-import Action
 import os
-import Task
 import pproc as subprocess
-from Params import fatal, warning
 import shutil
 import sys
 
+import Task
+import Options
+import Configure
+import TaskGen
+import Logs
+import Build
+
 ## Adjust python path to look for our local copy of pybindgen
 LOCAL_PYBINDGEN_PATH = os.path.join(os.getcwd(), "bindings", "python", "pybindgen")
 #PYBINDGEN_BRANCH = 'lp:pybindgen'
@@ -109,7 +110,7 @@ __version__ = %r
 
 def configure(conf):
     conf.env['ENABLE_PYTHON_BINDINGS'] = False
-    if Params.g_options.python_disable:
+    if Options.options.python_disable:
         conf.report_optional_feature("python", "Python Bindings", False,
                                      "disabled by user request")
         return
@@ -119,7 +120,7 @@ def configure(conf):
     if sys.platform == 'cygwin':
         conf.report_optional_feature("python", "Python Bindings", False,
                                      "unsupported platform 'cygwin'")
-        warning("Python is not supported in CygWin environment.  Try MingW instead.")
+        Logs.warn("Python is not supported in CygWin environment.  Try MingW instead.")
         return
 
     ## Check for Python
@@ -142,11 +143,11 @@ def configure(conf):
     ## Check for pybindgen
 
     no_net = False
-    if Params.g_options.with_pybindgen:
-        conf.env['WITH_PYBINDGEN'] = os.path.abspath(Params.g_options.with_pybindgen)
+    if Options.options.with_pybindgen:
+        conf.env['WITH_PYBINDGEN'] = os.path.abspath(Options.options.with_pybindgen)
         no_net = True
 
-    if Params.g_options.pybindgen_checkout:
+    if Options.options.pybindgen_checkout:
         fetch_pybindgen(conf)
 
     set_pybindgen_pythonpath(conf.env)
@@ -258,29 +259,32 @@ def calc_header_include(path):
         return os.path.join (calc_header_include (head), tail)
 
 
-def gen_ns3_metaheader(task):
-    assert len(task.m_outputs) == 1
+class gen_everything_h_task(Task.Task):
+    before = 'cc cxx'
 
-    header_files = [calc_header_include(node.abspath(task.m_env)) for node in task.m_inputs]
-    outfile = file(task.m_outputs[0].bldpath(task.m_env), "w")
+    def run(self):
+        assert len(self.outputs) == 1
 
-    def sort_func(h1, h2):
-        return cmp((get_header_prio(h1), h1), (get_header_prio(h1), h2))
+        header_files = [calc_header_include(node.abspath(self.env)) for node in self.inputs]
+        outfile = file(self.outputs[0].bldpath(self.env), "w")
 
-    header_files.sort(sort_func)
+        def sort_func(h1, h2):
+            return cmp((get_header_prio(h1), h1), (get_header_prio(h1), h2))
 
-    print >> outfile, """
+        header_files.sort(sort_func)
+
+        print >> outfile, """
 
 /* http://www.nsnam.org/bugzilla/show_bug.cgi?id=413 */
 #ifdef ECHO
 # undef ECHO
 #endif
 
-"""
-    for header in header_files:
-        print >> outfile, "#include \"ns3/%s\"" % (header,)
+    """
+        for header in header_files:
+            print >> outfile, "#include \"ns3/%s\"" % (header,)
 
-    print >> outfile, """
+        print >> outfile, """
 namespace ns3 {
 static inline Ptr<Object>
 __dummy_function_to_force_template_instantiation (Ptr<Object> obj, TypeId typeId)
@@ -312,34 +316,34 @@ __dummy_function_to_force_template_instantiation_v2 ()
 
 }
 """
-    outfile.close()
-    return 0
+        outfile.close()
+        return 0
 
 
 
-class all_ns3_headers_taskgen(Object.task_gen):
+class all_ns3_headers_taskgen(TaskGen.task_gen):
     """Generates a 'everything.h' header file that includes some/all public ns3 headers.
     This single header file is to be parsed only once by gccxml, for greater efficiency.
     """
-    def __init__(self, *features):
-        Object.task_gen.__init__(self, *features)
-        self.inst_var = 0#'INCLUDEDIR'
+    def __init__(self, *args, **kwargs):
+        super(all_ns3_headers_taskgen, self).__init__(*args, **kwargs)
+        self.install_path = None
         #self.inst_dir = 'ns3'
 
     def apply(self):
         ## get all of the ns3 headers
-        ns3_dir_node = Params.g_build.m_srcnode.find_dir("ns3")
+        ns3_dir_node = Build.bld.path.find_dir("ns3")
         all_headers_inputs = []
 
         for filename in self.to_list(self.source):
-            src_node = ns3_dir_node.find_build(filename)
+            src_node = ns3_dir_node.find_or_declare(filename)
             if src_node is None:
-                Params.fatal("source ns3 header file %s not found" % (filename,))
+                raise Utils.WafError("source ns3 header file %s not found" % (filename,))
             all_headers_inputs.append(src_node)
 
         ## if self.source was empty, include all ns3 headers in enabled modules
         if not all_headers_inputs:
-            for ns3headers in Object.g_allobjs:
+            for ns3headers in Build.bld.all_task_gen:
                 if type(ns3headers).__name__ == 'ns3header_taskgen': # XXX: find less hackish way to compare
                     ## skip headers not part of enabled modules
                     if self.env['NS3_ENABLED_MODULES']:
@@ -348,13 +352,13 @@ class all_ns3_headers_taskgen(Object.task_gen):
 
                     for source in ns3headers.to_list(ns3headers.source):
                         #source = os.path.basename(source)
-                        node = ns3_dir_node.find_build(source)
+                        node = ns3_dir_node.find_or_declare(source)
                         if node is None:
                             fatal("missing header file %s" % (source,))
                         all_headers_inputs.append(node)
         assert all_headers_inputs
-        all_headers_outputs = [self.path.find_build("everything.h")]
-        task = self.create_task('gen-ns3-metaheader', self.env, 4)
+        all_headers_outputs = [self.path.find_or_declare("everything.h")]
+        task = self.create_task('gen_everything_h', self.env)
         task.set_inputs(all_headers_inputs)
         task.set_outputs(all_headers_outputs)
 
@@ -370,13 +374,13 @@ def get_modules_and_headers():
     """
 
     retval = {}
-    for module in Object.g_allobjs:
+    for module in Build.bld.all_task_gen:
         if not module.name.startswith('ns3-'):
             continue
         module_name = module.name[4:] # strip the ns3- prefix
         ## find the headers object for this module
         headers = []
-        for ns3headers in Object.g_allobjs:
+        for ns3headers in Build.bld.all_task_gen:
             if type(ns3headers).__name__ != 'ns3header_taskgen': # XXX: find less hackish way to compare
                 continue
             if ns3headers.module != module_name:
@@ -388,15 +392,15 @@ def get_modules_and_headers():
 
 
 
-class PythonScanTask(Task.TaskBase):
+class python_scan_task(Task.TaskBase):
     """Uses gccxml to scan the file 'everything.h' and extract API definitions.
     """
+    after = 'gen_everything_h'
     def __init__(self, curdirnode, env):
-        self.prio = 5 # everything.h has prio 4
-        super(PythonScanTask, self).__init__()
+        super(python_scan_task, self).__init__()
         self.curdirnode = curdirnode
         self.env = env
-        self.m_display = 'python-scan\n'
+        self.display = 'python-scan\n'
 
     def run(self):
         #print "Rescanning the python bindings..."
@@ -404,7 +408,7 @@ class PythonScanTask(Task.TaskBase):
             self.env['PYTHON'],
             os.path.join(self.curdirnode.abspath(), 'ns3modulescan.py'), # scanning script
             self.curdirnode.find_dir('../..').abspath(self.env), # include path (where the ns3 include dir is)
-            self.curdirnode.find_build('everything.h').abspath(self.env),
+            self.curdirnode.find_or_declare('everything.h').abspath(self.env),
             os.path.join(self.curdirnode.abspath(), 'ns3modulegen_generated.py'), # output file
             ]
         scan = subprocess.Popen(argv, stdin=subprocess.PIPE)
@@ -415,24 +419,24 @@ class PythonScanTask(Task.TaskBase):
         raise SystemExit(0)
 
 def build(bld):
-    if Params.g_options.python_disable:
+    if Options.options.python_disable:
         return
 
-    env = bld.env_of_name('default')
-    curdir = bld.m_curdirnode.abspath()
+    env = bld.env
+    curdir = bld.path.abspath()
 
     set_pybindgen_pythonpath(env)
 
     #Object.register('all-ns3-headers', AllNs3Headers)
-    Action.Action('gen-ns3-metaheader', func=gen_ns3_metaheader, color='BLUE')
+    #Action.Action('gen-ns3-metaheader', func=gen_ns3_metaheader, color='BLUE')
 
     if env['ENABLE_PYTHON_BINDINGS']:
-        obj = bld.create_obj('all_ns3_headers')
+        obj = bld.new_task_gen('all_ns3_headers')
 
-    if Params.g_options.python_scan:
+    if Options.options.python_scan:
         if not env['ENABLE_PYTHON_SCANNING']:
-            Params.fatal("Cannot re-scan python bindings: (py)gccxml not available")
-        PythonScanTask(bld.m_curdirnode, env)
+            raise Utils.WafError("Cannot re-scan python bindings: (py)gccxml not available")
+        PythonScanTask(bld.path, env)
 
     ## Get a list of scanned modules; the set of scanned modules
     ## may be smaller than the set of all modules, in case a new
@@ -448,46 +452,62 @@ def build(bld):
         scanned_modules.append(name)
 
     if env['ENABLE_PYTHON_BINDINGS']:
-        bindgen = bld.create_obj('command-output')
-        bindgen.name = 'pybindgen'
-        bindgen.command = env['PYTHON']
-        bindgen.command_is_external = True
-        bindgen.stderr = 'ns3modulegen.log'
-        bindgen.argv = [
-            #'-m', 'pdb',
-            bindgen.input_file("ns3modulegen.py"),
-            bindgen.output_file("ns3module.cc"),
+        source = [
+            'ns3modulegen.py',
+            'ns3modulegen_generated.py',
+            'ns3modulegen_core_customizations.py',
             ]
-        bindgen.argv.extend(get_modules_and_headers().iterkeys())
-        bindgen.hidden_inputs = ['ns3modulegen_generated.py',
-                                 'ns3modulegen_core_customizations.py']
+        target = [
+            'ns3module.cc',
+            'ns3module.h',
+            'ns3modulegen.log',
+            ]
+        argv = ['NS3_ENABLED_FEATURES=${FEATURES}', '${PYTHON}', '${SRC[0]}', '${TGT[0]}']
+        argv.extend(get_modules_and_headers().iterkeys())
+
+        #bindgen.name = 'pybindgen'
+        #bindgen.command = env['PYTHON']
+        #bindgen.command_is_external = True
+        #bindgen.stderr = 'ns3modulegen.log'
+        #bindgen.argv = [
+            #'-m', 'pdb',
+        #    bindgen.input_file("ns3modulegen.py"),
+        #    bindgen.output_file("ns3module.cc"),
+        #    ]
+        #bindgen.hidden_inputs = ['ns3modulegen_generated.py',
+        #                         'ns3modulegen_core_customizations.py']
 
         for module in scanned_modules:
-            bindgen.hidden_inputs.append("ns3_module_%s.py" % module)
+            source.append("ns3_module_%s.py" % module)
             local = "ns3_module_%s__local.py" % module
             if os.path.exists(os.path.join(curdir, local)):
-                bindgen.hidden_inputs.append(local)
+                source.append(local)
 
-        bindgen.hidden_outputs = ['ns3module.h']
+        argv.extend(['2>', '${TGT[2]}']) # 2> ns3modulegen.log
+
+        #bindgen.hidden_outputs = ['ns3module.h']
         for module in scanned_modules:
-            bindgen.hidden_outputs.append("ns3_module_%s.cc" % module)
+            target.append("ns3_module_%s.cc" % module)
 
-        bindgen.prio = 50
+        #bindgen.prio = 50
 
-        bindgen.os_env = dict(os.environ)
+        #bindgen.os_env = dict(os.environ)
         features = []
         for (name, caption, was_enabled, reason_not_enabled) in env['NS3_OPTIONAL_FEATURES']:
             if was_enabled:
                 features.append(name)
-        bindgen.os_env['NS3_ENABLED_FEATURES'] = ','.join(features)
+        #bindgen.os_env['NS3_ENABLED_FEATURES'] = ','.join(features)
+
+        bindgen = bld.new_task_gen('command', source=source, target=target,
+                                   command=argv, variables=dict(FEATURES=(','.join(features))))
 
 
     ## we build python bindings if either we have the tools to
     ## generate them or if the pregenerated source file is already
     ## present in the source dir.
     if env['ENABLE_PYTHON_BINDINGS'] \
-            or os.path.exists(os.path.join(bld.m_curdirnode.abspath(), 'ns3module.cc')):
-        pymod = bld.create_obj('cpp', 'shlib', 'pyext')
+            or os.path.exists(os.path.join(bld.path.abspath(), 'ns3module.cc')):
+        pymod = bld.new_task_gen('cxx', 'shlib', 'pyext')
         pymod.source = ['ns3module.cc', 'ns3module_helpers.cc']
         pymod.includes = '.'
         for module in scanned_modules:
@@ -497,10 +517,10 @@ def build(bld):
         pymod.uselib_local = "ns3"
         pymod.env.append_value('CXXDEFINES', ['NS_DEPRECATED=""', 'NS3_DEPRECATED_H'])
 
-        # copy the __init__.py file to the build dir waf can't handle
+        # copy the __init__.py file to the build dir. waf can't handle
         # this, it's against waf's principles to have build dir files
         # with the same name as source dir files, apparently.
-        dirnode = bld.m_curdirnode.find_dir('ns3')
+        dirnode = bld.path.find_dir('ns3')
         src = os.path.join(dirnode.abspath(), '__init__.py')
         dst = os.path.join(dirnode.abspath(env), '__init__.py')
         try:
diff --git a/doc/build.txt b/doc/build.txt
index 090b83408..984e809d4 100644
--- a/doc/build.txt
+++ b/doc/build.txt
@@ -9,6 +9,12 @@ http://www.nsnam.org/wiki/index.php/Installation
 
 The top-level ns-3 directory should contain a current waf script.
 
+Note: we're using a WAF version based on WAF 1.5.x.  The source code
+can be retrieved from the followin URL:
+
+    https://code.launchpad.net/~gjc/waf/cmd
+
+
 === Building with Waf ===
 
 To build ns-3 with waf type the commands from the top-level directory:
diff --git a/regression.py b/regression.py
index 9d63cfcd0..36d69b3f0 100644
--- a/regression.py
+++ b/regression.py
@@ -1,12 +1,19 @@
+# python lib modules
 import os
 import sys
-import Params
 import shutil
 import pproc as subprocess
 import urllib
 
+# WAF modules
+import Build
+import Options
+import Utils
+
+# local modules
 import wutils
 
+
 #
 # The directory in which the tarball of the reference traces lives.  This is
 # used if Mercurial is not on the system.
@@ -45,7 +52,7 @@ class Regression(object):
     def __init__(self, testdir, reference_traces):
         self.testdir = testdir
         self.reference_traces = reference_traces
-        self.env = Params.g_build.env_of_name('default')
+        self.env = Build.bld.env
 
     def run_test(self, verbose, generate, testName, arguments=[], pyscript=None, refTestName=None):
         """
@@ -83,13 +90,13 @@ class Regression(object):
                 os.mkdir(refTestDirName)
 
             if pyscript is None:
-                Params.g_options.cwd_launch = refTestDirName
+                Options.options.cwd_launch = refTestDirName
                 tmpl = "%s"
                 for arg in arguments:
                     tmpl = tmpl + " " + arg
                 wutils.run_program(testName, tmpl)
             else:
-                argv = [self.env['PYTHON'], os.path.join(Params.g_cwd_launch, *os.path.split(pyscript))] + arguments
+                argv = [self.env['PYTHON'], os.path.join(Options.cwd_launch, *os.path.split(pyscript))] + arguments
                 before = os.getcwd()
                 os.chdir(refTestDirName)
                 try:
@@ -120,7 +127,7 @@ class Regression(object):
             #  testName + " > /dev/null 2>&1")
 
             if pyscript is None:
-                Params.g_options.cwd_launch = traceDirName
+                Options.options.cwd_launch = traceDirName
                 wutils.run_program(testName, command_template=wutils.get_command_template(*arguments))
             else:
                 argv = [self.env['PYTHON'], os.path.join('..', '..', '..', *os.path.split(pyscript))] + arguments
@@ -191,13 +198,13 @@ def run_regression(reference_traces):
     sys.path.append(testdir)
     sys.modules['tracediff'] = Regression(testdir, reference_traces)
 
-    if Params.g_options.regression_tests:
-        tests = Params.g_options.regression_tests.split(',')
+    if Options.options.regression_tests:
+        tests = Options.options.regression_tests.split(',')
     else:
         tests = _find_tests(testdir)
 
     print "========== Running Regression Tests =========="
-    env = Params.g_build.env_of_name('default')
+    env = Build.bld.env
     if not no_net:
         if env['MERCURIAL']:
             print "Synchronizing reference traces using Mercurial."
@@ -216,7 +223,7 @@ def run_regression(reference_traces):
                 finally:
                     os.chdir("..")
                 if result:
-                    Params.fatal("Synchronizing reference traces using Mercurial failed.")
+                    raise Utils.WafError("Synchronizing reference traces using Mercurial failed.")
         else:
             if not os.path.exists(reference_traces):
                 traceball = dir_name + wutils.TRACEBALL_SUFFIX
@@ -235,7 +242,7 @@ def run_regression(reference_traces):
         try:
             result = _run_regression_test(test)
             if result == 0:
-                if Params.g_options.regression_generate:
+                if Options.options.regression_generate:
                     print "GENERATE " + test
                 else:
                     print "PASS " + test
@@ -243,7 +250,7 @@ def run_regression(reference_traces):
                 bad.append(test)
                 print "FAIL " + test
         except NotImplementedError:
-                print "SKIP " + test            
+            print "SKIP " + test            
 
     return len(bad) > 0
 
@@ -265,6 +272,6 @@ def _run_regression_test(test):
         os.mkdir("traces")
     
     mod = __import__(test, globals(), locals(), [])
-    return mod.run(verbose=(Params.g_options.verbose > 0),
-                   generate=Params.g_options.regression_generate)
+    return mod.run(verbose=(Options.options.verbose > 0),
+                   generate=Options.options.regression_generate)
 
diff --git a/src/applications/onoff/wscript b/src/applications/onoff/wscript
index ee1041066..961dcaac5 100644
--- a/src/applications/onoff/wscript
+++ b/src/applications/onoff/wscript
@@ -5,7 +5,7 @@ def build(bld):
     module.source = [
         'onoff-application.cc',
         ]
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'onoff'
     headers.source = [
         'onoff-application.h',
diff --git a/src/applications/packet-sink/wscript b/src/applications/packet-sink/wscript
index 120095544..0f618ddff 100644
--- a/src/applications/packet-sink/wscript
+++ b/src/applications/packet-sink/wscript
@@ -5,7 +5,7 @@ def build(bld):
     module.source = [
         'packet-sink.cc',
         ]
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'packet-sink'
     headers.source = [
         'packet-sink.h',
diff --git a/src/applications/udp-echo/wscript b/src/applications/udp-echo/wscript
index 762e59ec9..4c27c517b 100644
--- a/src/applications/udp-echo/wscript
+++ b/src/applications/udp-echo/wscript
@@ -6,7 +6,7 @@ def build(bld):
         'udp-echo-client.cc',
         'udp-echo-server.cc',
         ]
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'udp-echo'
     headers.source = [
         'udp-echo-client.h',
diff --git a/src/applications/v4ping/wscript b/src/applications/v4ping/wscript
index a4c56c3f3..2fa4075d3 100644
--- a/src/applications/v4ping/wscript
+++ b/src/applications/v4ping/wscript
@@ -5,7 +5,7 @@ def build(bld):
     module.source = [
         'v4ping.cc',
         ]
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'v4ping'
     headers.source = [
         'v4ping.h',
diff --git a/src/common/wscript b/src/common/wscript
index 0b76283bf..3614fef06 100644
--- a/src/common/wscript
+++ b/src/common/wscript
@@ -18,7 +18,7 @@ def build(bld):
         'tag-buffer.cc',
         ]
 
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'common'
     headers.source = [
         'buffer.h',
diff --git a/src/contrib/stats/wscript b/src/contrib/stats/wscript
index 3be5543e9..62b6146fd 100644
--- a/src/contrib/stats/wscript
+++ b/src/contrib/stats/wscript
@@ -1,12 +1,7 @@
 ## -*- Mode: python; py-indent-offset: 4; indent-tabs-mode: nil; coding: utf-8; -*-
 
 def configure(conf):
-   e = conf.create_library_configurator()
-   e.mandatory = False
-   e.name = 'sqlite3'
-   e.define = 'SQLITE3'
-   e.uselib = 'SQLITE3'
-   conf.env['SQLITE_STATS'] = e.run()
+   conf.env['SQLITE_STATS'] = conf.check(lib='sqlite3', define_name='SQLITE3', uselib='SQLITE3')
    conf.report_optional_feature("SqliteDataOutput", "SQlite stats data output",
                                 conf.env['SQLITE_STATS'],
                                 "library 'sqlite3' not found")
@@ -22,7 +17,7 @@ def build(bld):
         'omnet-data-output.cc',
         'data-collector.cc',
         ]
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'stats'
     headers.source = [
         'data-calculator.h',
@@ -34,7 +29,7 @@ def build(bld):
         'data-collector.h',
         ]
 
-    if bld.env()['SQLITE_STATS']:
+    if bld.env['SQLITE_STATS']:
         headers.source.append('sqlite-data-output.h')
         obj.source.append('sqlite-data-output.cc')
         obj.uselib = 'SQLITE3'
diff --git a/src/contrib/wscript b/src/contrib/wscript
index f868774f9..7324d8a56 100644
--- a/src/contrib/wscript
+++ b/src/contrib/wscript
@@ -1,11 +1,8 @@
 ## -*- Mode: python; py-indent-offset: 4; indent-tabs-mode: nil; coding: utf-8; -*-
 
 def configure(conf):
-    check = conf.create_pkgconfig_configurator()
-    check.name = 'gtk+-2.0 >= 2.12'
-    check.uselib = 'GTK_CONFIG_STORE'
-    check.mandatory = False
-    conf.env['ENABLE_GTK_CONFIG_STORE'] = check.run()
+    have_it = conf.pkg_check_modules('GTK_CONFIG_STORE', 'gtk+-2.0 >= 2.12', mandatory=False)
+    conf.env['ENABLE_GTK_CONFIG_STORE'] = have_it
     conf.report_optional_feature("GtkConfigStore", "GtkConfigStore",
                                  conf.env['ENABLE_GTK_CONFIG_STORE'],
                                  "library 'gtk+-2.0 >= 2.12' not found")
@@ -23,7 +20,7 @@ def build(bld):
         'flow-id-tag.cc',
         ]
 
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'contrib'
     headers.source = [
         'event-garbage-collector.h',
@@ -33,7 +30,7 @@ def build(bld):
         'flow-id-tag.h',
         ]
 
-    if bld.env()['ENABLE_GTK_CONFIG_STORE']:
+    if bld.env['ENABLE_GTK_CONFIG_STORE']:
         headers.source.append ('gtk-config-store.h')
         module.source.append ('gtk-config-store.cc')
         module.uselib = 'GTK_CONFIG_STORE'
diff --git a/src/core/wscript b/src/core/wscript
index 586b0ee95..8d76057fe 100644
--- a/src/core/wscript
+++ b/src/core/wscript
@@ -3,36 +3,16 @@ import sys
 
 
 def configure(conf):
-    e = conf.create_header_configurator()
-    e.mandatory = False
-    e.name = 'stdlib.h'
-    e.define = 'HAVE_STDLIB_H'
-    e.run()
+    if conf.check(header_name='stdlib.h'):
+        conf.define('HAVE_STDLIB_H', 1)
+        conf.define('HAVE_GETENV', 1)
 
-    e = conf.create_header_configurator()
-    e.mandatory = False
-    e.name = 'stdlib.h'
-    e.define = 'HAVE_GETENV'
-    e.run()
+    conf.check(header_name='signal.h', define_name='HAVE_SIGNAL_H')
 
-    e = conf.create_header_configurator()
-    e.mandatory = False
-    e.name = 'signal.h'
-    e.define = 'HAVE_SIGNAL_H'
-    e.run()
+    conf.check(lib='rt', uselib='RT', define_name='HAVE_RT')
 
-    e = conf.create_library_configurator()
-    e.mandatory = False
-    e.name = 'rt'
-    e.define = 'HAVE_RT'
-    e.uselib = 'RT'
-    e.run()
+    conf.env['ENABLE_THREADING'] = conf.check(header_name='pthread.h', define_name='HAVE_PTHREAD_H')
 
-    e = conf.create_header_configurator()
-    e.mandatory = False
-    e.name = 'pthread.h'
-    e.define = 'HAVE_PTHREAD_H'
-    conf.env['ENABLE_THREADING'] = e.run()
     conf.report_optional_feature("Threading", "Threading Primitives",
                                  conf.env['ENABLE_THREADING'],
                                  "<pthread.h> include not detected")
@@ -76,7 +56,7 @@ def build(bld):
         ]
     core.uselib = 'RT'
 
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'core'
     headers.source = [
         'system-wall-clock-ms.h',
@@ -129,7 +109,7 @@ def build(bld):
             'unix-system-wall-clock-ms.cc',
             ])
 
-    if bld.env()['ENABLE_THREADING']:
+    if bld.env['ENABLE_THREADING']:
         core.source.extend([
             'unix-system-thread.cc',
             'unix-system-mutex.cc',
diff --git a/src/devices/bridge/wscript b/src/devices/bridge/wscript
index fec55457e..b0a13f0c4 100644
--- a/src/devices/bridge/wscript
+++ b/src/devices/bridge/wscript
@@ -6,7 +6,7 @@ def build(bld):
         'bridge-net-device.cc',
         'bridge-channel.cc',
         ]
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'bridge'
     headers.source = [
         'bridge-net-device.h',
diff --git a/src/devices/csma/wscript b/src/devices/csma/wscript
index a90ac5bd3..af86e352b 100644
--- a/src/devices/csma/wscript
+++ b/src/devices/csma/wscript
@@ -7,7 +7,7 @@ def build(bld):
         'csma-net-device.cc',
         'csma-channel.cc',
         ]
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'csma'
     headers.source = [
         'backoff.h',
diff --git a/src/devices/emu/wscript b/src/devices/emu/wscript
index ff5a4fa75..8400d1288 100644
--- a/src/devices/emu/wscript
+++ b/src/devices/emu/wscript
@@ -1,11 +1,8 @@
 ## -*- Mode: python; py-indent-offset: 4; indent-tabs-mode: nil; coding: utf-8; -*-
 
 def configure(conf):
-    e = conf.create_header_configurator()
-    e.mandatory = False
-    e.name = 'linux/if_ether.h'
-    e.define = 'HAVE_IF_ETHER_H'
-    conf.env['ENABLE_EMU'] = e.run()
+    conf.env['ENABLE_EMU'] = conf.check(header_name='linux/if_ether.h',
+                                        define_name='HAVE_IF_ETHER_H')
     conf.report_optional_feature("EmuNetDevice", "Emulated Net Device",
                                  conf.env['ENABLE_EMU'],
                                  "<linux/if_ether.h> include not detected")
@@ -14,7 +11,7 @@ def build(bld):
     module = bld.create_ns3_module('emu', ['node'])
     module.source = [
         ]
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'emu'
     headers.source = [
         'emu.h',
diff --git a/src/devices/point-to-point/wscript b/src/devices/point-to-point/wscript
index 31aa62ade..a1fb07c57 100644
--- a/src/devices/point-to-point/wscript
+++ b/src/devices/point-to-point/wscript
@@ -9,7 +9,7 @@ def build(bld):
         'point-to-point-test.cc',
         'ppp-header.cc',
         ]
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'point-to-point'
     headers.source = [
         'point-to-point-net-device.h',
diff --git a/src/devices/wifi/wscript b/src/devices/wifi/wscript
index b01ac49e0..43998e5df 100644
--- a/src/devices/wifi/wscript
+++ b/src/devices/wifi/wscript
@@ -44,7 +44,7 @@ def build(bld):
         'constant-rate-wifi-manager.cc',
         'wifi-test.cc',
         ]
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'wifi'
     headers.source = [
         'propagation-delay-model.h',
diff --git a/src/helper/wscript b/src/helper/wscript
index c71039134..d1f2ef6a6 100644
--- a/src/helper/wscript
+++ b/src/helper/wscript
@@ -25,7 +25,7 @@ def build(bld):
         'v4ping-helper.cc',
         ]
 
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'helper'
     headers.source = [
         'node-container.h',
diff --git a/src/internet-stack/wscript b/src/internet-stack/wscript
index 6b9625712..7841cbf22 100644
--- a/src/internet-stack/wscript
+++ b/src/internet-stack/wscript
@@ -1,9 +1,12 @@
 ## -*- Mode: python; py-indent-offset: 4; indent-tabs-mode: nil; coding: utf-8; -*-
-import Params
-import Task
 import os
 import urllib
 
+import Options
+import Logs
+import Utils
+import Task
+
 # Mercurial repository of the network simulation cradle
 NSC_REPO = "https://secure.wand.net.nz/mercurial/nsc"
 NSC_RELEASE_URL = "http://research.wand.net.nz/software/nsc"
@@ -25,17 +28,17 @@ def nsc_fetch():
     def nsc_clone():
         print "Retrieving nsc from " + NSC_REPO
         if os.system("hg version > /dev/null 2>&1") != 0:
-            Params.fatal("Mercurial not installed, http fallback not yet implemented")
+            raise Utils.WafError("Mercurial not installed, http fallback not yet implemented")
         if os.system("hg  clone " + NSC_REPO) != 0:
-            Params.fatal("hg -q clone %s failed" % NSC_REPO)
+            raise Utils.WafError("hg -q clone %s failed" % NSC_REPO)
 
     def nsc_update():
         if os.system("hg version > /dev/null 2>&1") != 0:
-            Params.warning("Mercurial not installed, not updating nsc source")
+            Logs.warn("Mercurial not installed, not updating nsc source")
 
         print "Pulling nsc updates from " + NSC_REPO
         if os.system("cd nsc && hg pull %s && hg update" % NSC_REPO) != 0:
-            Params.warning("Updating nsc using mercurial failed")
+            Logs.warn("Updating nsc using mercurial failed")
 
     def nsc_download():
         local_file = NSC_RELEASE_NAME + ".tar.bz2"
@@ -61,12 +64,9 @@ def configure(conf):
         import flex
         import bison
         conf.check_tool('flex bison')
-        e = conf.create_library_configurator()
-        e.mandatory = True
-        e.name = 'fl'
-        e.run()
+        conf.check(lib='fl', mandatory=True)
 
-    if not Params.g_options.enable_nsc:
+    if not Options.options.enable_nsc:
         conf.report_optional_feature("nsc", "Network Simulation Cradle", False,
                                      "--enable-nsc configure option not given")
 	return
@@ -78,13 +78,7 @@ def configure(conf):
     if arch == 'x86_64' or arch == 'i686' or arch == 'i586' or arch == 'i486' or arch == 'i386':
         conf.env['NSC_ENABLED'] = 'yes'
         conf.env.append_value('CXXDEFINES', 'NETWORK_SIMULATION_CRADLE')
-        e = conf.create_library_configurator()
-        e.mandatory = True
-        e.name = 'dl'
-        e.define = 'HAVE_DL'
-        e.uselib = 'DL'
-        e.run()
-        conf.env['ENABLE_NSC'] = True
+        conf.env['ENABLE_NSC'] = conf.check(mandatory=True, lib='dl', define_name='HAVE_DL', uselib='DL')
         ok = True
     conf.check_message('NSC supported architecture', arch, ok)
     conf.report_optional_feature("nsc", "Network Simulation Cradle", ok,
@@ -96,11 +90,11 @@ def configure(conf):
 class NscBuildTask(Task.TaskBase):
     """task that builds nsc
     """
+    after = 'link' # build after the rest of ns-3
     def __init__(self, builddir):
-        self.prio = 1000 # build after the rest of ns-3
         self.builddir = builddir
         super(NscBuildTask, self).__init__()
-        self.m_display = 'build-nsc\n'
+        self.display = 'build-nsc\n'
 
     def run(self):
         # XXX: Detect gcc major version(s) available to build supported stacks
@@ -111,13 +105,13 @@ class NscBuildTask(Task.TaskBase):
             soname = 'lib' + name + '.so'
             if not os.path.exists(os.path.join("..", NSC_DIR, dir, soname)):
                 if os.system('cd ../%s && python scons.py %s' % (NSC_DIR, dir)) != 0:
-                    Params.fatal("Building NSC stack failed")
+                    raise Utils.WafError("Building NSC stack failed")
 
             if not os.path.exists(builddir + '/' + soname):
                 try:
                     os.symlink('../../' + NSC_DIR + '/' + dir + '/' + soname, builddir +  '/' + soname)
                 except:
-                    Params.fatal("Error linking " + builddir + '/' + soname)
+                    raise Utils.WafError("Error linking " + builddir + '/' + soname)
 
 
 def build(bld):
@@ -155,7 +149,7 @@ def build(bld):
         'icmpv4-l4-protocol.cc',
         ]
 
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'internet-stack'
     headers.source = [
         'internet-stack.h',
@@ -169,11 +163,11 @@ def build(bld):
         'icmpv4.h',
         ]
 
-    if bld.env()['NSC_ENABLED']:        
+    if bld.env['NSC_ENABLED']:        
         obj.source.append ('nsc-tcp-socket-impl.cc')
         obj.source.append ('nsc-tcp-l4-protocol.cc')
         obj.source.append ('nsc-tcp-socket-factory-impl.cc')
         obj.source.append ('nsc-sysctl.cc')
         obj.uselib = 'DL'
-        builddir = os.path.abspath(os.path.join(bld.env()['NS3_BUILDDIR'], bld.env ().variant()))
+        builddir = os.path.abspath(os.path.join(bld.env['NS3_BUILDDIR'], bld.env ().variant()))
         NscBuildTask(builddir)
diff --git a/src/mobility/wscript b/src/mobility/wscript
index 2ce6b1844..0163e3639 100644
--- a/src/mobility/wscript
+++ b/src/mobility/wscript
@@ -16,7 +16,7 @@ def build(bld):
         'random-direction-2d-mobility-model.cc',
         ]
 
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'mobility'
     headers.source = [
         'vector.h',
diff --git a/src/node/wscript b/src/node/wscript
index 9ef38c624..cf318b0f2 100644
--- a/src/node/wscript
+++ b/src/node/wscript
@@ -40,7 +40,7 @@ def build(bld):
         'ipv4-raw-socket-factory.cc',
         ]
 
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'node'
     headers.source = [
         'address.h',
diff --git a/src/routing/global-routing/wscript b/src/routing/global-routing/wscript
index 17816ade1..483e5b5d0 100644
--- a/src/routing/global-routing/wscript
+++ b/src/routing/global-routing/wscript
@@ -8,7 +8,7 @@ def build(bld):
         'global-route-manager-impl.cc',
         'candidate-queue.cc',
         ]
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'global-routing'
     headers.source = [
         'global-router-interface.h',
diff --git a/src/routing/olsr/wscript b/src/routing/olsr/wscript
index 8e82c6de5..52e835d5b 100644
--- a/src/routing/olsr/wscript
+++ b/src/routing/olsr/wscript
@@ -11,7 +11,7 @@ def build(bld):
         'olsr-agent-impl.cc',
         ]
 
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'olsr'
     headers.source = [
         'olsr-agent.h',
diff --git a/src/simulator/wscript b/src/simulator/wscript
index 506119579..5cf9c5b66 100644
--- a/src/simulator/wscript
+++ b/src/simulator/wscript
@@ -1,7 +1,7 @@
 ## -*- Mode: python; py-indent-offset: 4; indent-tabs-mode: nil; coding: utf-8; -*-
 import sys
 
-import Params
+import Options
 
 
 def set_options(opt):
@@ -15,32 +15,21 @@ def set_options(opt):
 
 
 def configure(conf):
-    if Params.g_options.high_precision_as_double:
+    if Options.options.high_precision_as_double:
         conf.define('USE_HIGH_PRECISION_DOUBLE', 1)
         conf.env['USE_HIGH_PRECISION_DOUBLE'] = 1
         highprec = 'long double'
     else:
         conf.env['USE_HIGH_PRECISION_DOUBLE'] = 0
         highprec = '128-bit integer'
-    conf.check_message_custom('high precision time','implementation',highprec)
 
-    e = conf.create_header_configurator()
-    e.mandatory = False
-    e.name = 'stdint.h'
-    e.define = 'HAVE_STDINT_H'
-    e.run()
+    conf.check_message_custom('high precision time', 'implementation', highprec)
 
-    e = conf.create_header_configurator()
-    e.mandatory = False
-    e.name = 'inttypes.h'
-    e.define = 'HAVE_INTTYPES_H'
-    e.run()
+    conf.check(header_name='stdint.h', define_name='HAVE_STDINT_H')
 
-    e = conf.create_header_configurator()
-    e.mandatory = False
-    e.name = 'sys/inttypes.h'
-    e.define = 'HAVE_SYS_INT_TYPES_H'
-    e.run()
+    conf.check(header_name='inttypes.h', define_name='HAVE_INTTYPES_H')
+
+    conf.check(header_name='sys/inttypes.h', define_name='HAVE_SYS_INT_TYPES_H')
 
     conf.write_config_header('ns3/simulator-config.h')
 
@@ -68,7 +57,7 @@ def build(bld):
         'make-event.cc',
         ]
 
-    headers = bld.create_obj('ns3header')
+    headers = bld.new_task_gen('ns3header')
     headers.module = 'simulator'
     headers.source = [
         'high-precision.h',
diff --git a/src/wscript b/src/wscript
index ede9746b3..3d79e10a8 100644
--- a/src/wscript
+++ b/src/wscript
@@ -3,11 +3,16 @@
 import os, os.path
 import shutil
 import types
+import warnings
 
-import Action
-import Common
-import Object
-import Params
+import TaskGen
+import Task
+import Options
+import Build
+#import Action
+#import Common
+#import Object
+#import Params
 
 
 all_modules = (
@@ -55,9 +60,9 @@ def configure(conf):
     conf.sub_config('contrib')
     conf.sub_config('internet-stack')
 
-    blddir = os.path.abspath(os.path.join(conf.m_blddir, conf.env.variant()))
+    blddir = os.path.abspath(os.path.join(conf.blddir, conf.env.variant()))
     conf.env.append_value('NS3_MODULE_PATH', blddir)
-    if Params.g_options.enable_rpath:
+    if Options.options.enable_rpath:
         conf.env.append_value('RPATH', '-Wl,-rpath=%s' % (os.path.join(blddir),))
 
     ## Used to link the 'run-tests' program with all of ns-3 code
@@ -65,7 +70,7 @@ def configure(conf):
 
 
 def create_ns3_module(bld, name, dependencies=()):
-    module = bld.create_obj('cpp', 'objects')
+    module = bld.new_task_gen('cxx', 'objects')
     module.name = 'ns3-' + name
     module.target = module.name
     module.add_objects = ['ns3-' + dep for dep in dependencies]
@@ -73,131 +78,134 @@ def create_ns3_module(bld, name, dependencies=()):
     module.env.append_value('CXXFLAGS', module.env['shlib_CXXFLAGS'])
     module.env.append_value('CXXDEFINES', "NS3_MODULE_COMPILATION")
     return module
-    
+
+def create_obj(bld, *args):
+    warnings.warn("(in %s) Use bld.new_task_gen(...) now, instead of bld.create_obj(...)" % str(bld.path),
+                  DeprecationWarning, stacklevel=2)
+    return bld.new_task_gen(*args)
 
 def build(bld):
     #Object.register('ns3header', Ns3Header)
-    Action.Action('ns3header', func=_ns3_headers_inst, color='BLUE')
+    #Action.Action('ns3header', func=_ns3_headers_inst, color='BLUE')
     #Object.register('ns3-module-header', Ns3ModuleHeader)
-    Action.Action('gen-ns3-module-header', func=gen_ns3_module_header, color='BLUE')
+    #Action.Action('gen-ns3-module-header', func=gen_ns3_module_header, color='BLUE')
     bld.create_ns3_module = types.MethodType(create_ns3_module, bld)
+    bld.create_obj = types.MethodType(create_obj, bld)
     
     bld.add_subdirs(list(all_modules))
 
     for module in all_modules:
-        modheader = bld.create_obj('ns3moduleheader')
+        modheader = bld.new_task_gen('ns3moduleheader')
         modheader.module = module.split('/')[-1]
 
 
-class ns3header_taskgen(Object.task_gen):
+class ns3header_taskgen(TaskGen.task_gen):
     """A set of NS-3 header files"""
-    def __init__(self, *features):
-        Object.task_gen.__init__(self, *features)
-        self.inst_var = 'INCLUDEDIR'
-        self.inst_dir = 'ns3'
+    COLOR = 'BLUE'
+    def __init__(self, *args, **kwargs):
+        super(ns3header_taskgen, self).__init__(*args, **kwargs)
+        self.install_path = None
         self.sub_dir = None # if not None, header files will be published as ns3/sub_dir/file.h
         self.module = None # module name
 
     def apply(self):
         if self.module is None:
-            Params.fatal("'module' missing on ns3headers object %s" % self)
-        ns3_dir_node = Params.g_build.m_srcnode.find_dir("ns3")
+            raise Utils.WafError("'module' missing on ns3headers object %s" % self)
+        ns3_dir_node = Build.bld.path.find_dir("ns3")
         if self.sub_dir is not None:
             ns3_dir_node = ns3_dir_node.find_dir(self.sub_dir)
         for filename in self.to_list(self.source):
-            src_node = self.path.find_source(filename)
+            src_node = self.path.find_resource(filename)
             if src_node is None:
-                Params.fatal("source ns3 header file %s not found" % (filename,))
-            dst_node = ns3_dir_node.find_build(os.path.basename(filename))
+                raise Utils.WafError("source ns3 header file %s not found" % (filename,))
+            dst_node = ns3_dir_node.find_or_declare(os.path.basename(filename))
             assert dst_node is not None
-            task = self.create_task('ns3header', self.env, 1)
+            task = self.create_task('ns3header', self.env)
             task.set_inputs([src_node])
             task.set_outputs([dst_node])
 
-    def install(self):
-        if self.sub_dir is None:
-            inst_dir = self.inst_dir
-        else:
-            inst_dir = os.path.join(self.inst_dir, self.sub_dir)
-        for i in self.m_tasks:
-            current = Params.g_build.m_curdirnode
-            lst = map(lambda a: a.relpath_gen(current), i.m_outputs)
-            Common.install_files(self.inst_var, inst_dir, lst)
-
-def _ns3_headers_inst(task):
-    assert len(task.m_inputs) == len(task.m_outputs)
-    inputs = [node.srcpath(task.m_env) for node in task.m_inputs]
-    outputs = [node.bldpath(task.m_env) for node in task.m_outputs]
-    for src, dst in zip(inputs, outputs):
-        try:
-            os.chmod(dst, 0600)
-        except OSError:
-            pass
-        shutil.copy2(src, dst)
-        ## make the headers in builddir read-only, to prevent
-        ## accidental modification
-        os.chmod(dst, 0400)
-    return 0
+class ns3header_task(Task.Task):
+    before = 'cc cxx'
+    color = 'BLUE'
+    def run(self):
+        assert len(self.inputs) == len(self.outputs)
+        inputs = [node.srcpath(self.env) for node in self.inputs]
+        outputs = [node.bldpath(self.env) for node in self.outputs]
+        for src, dst in zip(inputs, outputs):
+            try:
+                os.chmod(dst, 0600)
+            except OSError:
+                pass
+            shutil.copy2(src, dst)
+            ## make the headers in builddir read-only, to prevent
+            ## accidental modification
+            os.chmod(dst, 0400)
+        return 0
 
 
-def gen_ns3_module_header(task):
-    assert len(task.m_outputs) == 1
-    header_files = [os.path.basename(node.abspath(task.m_env)) for node in task.m_inputs]
-    outfile = file(task.m_outputs[0].bldpath(task.m_env), "w")
-    header_files.sort()
 
-    print >> outfile, """
+class gen_ns3_module_header_task(Task.Task):
+    before = 'cc cxx'
+    color = 'BLUE'
+    def run(self):
+        assert len(self.outputs) == 1
+        header_files = [os.path.basename(node.abspath(self.env)) for node in self.inputs]
+        outfile = file(self.outputs[0].bldpath(self.env), "w")
+        header_files.sort()
+
+        print >> outfile, """
 #ifdef NS3_MODULE_COMPILATION
 # error "Do not include ns3 module aggregator headers from other modules; these are meant only for end user scripts."
 #endif
 
 #ifndef NS3_MODULE_%s
-""" % (task.module.upper().replace('-', '_'),)
+    """ % (self.module.upper().replace('-', '_'),)
 
-#     if task.module_deps:
-#         print >> outfile, "// Module dependencies:"
-#     for dep in task.module_deps:
-#         print >> outfile, "#include \"%s-module.h\"" % dep
+    #     if self.module_deps:
+    #         print >> outfile, "// Module dependencies:"
+    #     for dep in self.module_deps:
+    #         print >> outfile, "#include \"%s-module.h\"" % dep
 
-    print >> outfile
-    print >> outfile, "// Module headers:"
-    for header in header_files:
-        print >> outfile, "#include \"%s\"" % (header,)
+        print >> outfile
+        print >> outfile, "// Module headers:"
+        for header in header_files:
+            print >> outfile, "#include \"%s\"" % (header,)
 
-    print >> outfile, "#endif"
+        print >> outfile, "#endif"
 
-    outfile.close()
-    return 0
+        outfile.close()
+        return 0
 
 
-class ns3moduleheader_taskgen(Object.task_gen):
+class ns3moduleheader_taskgen(TaskGen.task_gen):
     """
     Generates a 'ns3/foo-module.h' header file that includes all
     public ns3 headers of a certain module.
     """
-    def __init__(self, *features):
-        Object.task_gen.__init__(self, *features)
+    COLOR = 'BLUE'
+    def __init__(self, *args, **kwargs):
+        super(ns3moduleheader_taskgen, self).__init__(*args, **kwargs)
         self.module_name = None
 
     def apply(self):
         ## get all of the ns3 headers
-        ns3_dir_node = Params.g_build.m_srcnode.find_dir("ns3")
+        ns3_dir_node = Build.bld.path.find_dir("ns3")
         all_headers_inputs = []
-        for ns3headers in Object.g_allobjs:
+        for ns3headers in Build.bld.all_task_gen:
             if isinstance(ns3headers, ns3header_taskgen):
                 if ns3headers.module != self.module:
                     continue
                 for source in ns3headers.to_list(ns3headers.source):
                     source = os.path.basename(source)
-                    node = ns3_dir_node.find_build(os.path.basename(source))
+                    node = ns3_dir_node.find_or_declare(os.path.basename(source))
                     if node is None:
                         fatal("missing header file %s" % (source,))
                     all_headers_inputs.append(node)
         assert all_headers_inputs
-        module_obj = Object.name_to_obj("ns3-" + self.module)
+        module_obj = Build.bld.name_to_obj("ns3-" + self.module, self.env)
         assert module_obj is not None
-        all_headers_outputs = [ns3_dir_node.find_build("%s-module.h" % self.module)]
-        task = self.create_task('gen-ns3-module-header', self.env, 4)
+        all_headers_outputs = [ns3_dir_node.find_or_declare("%s-module.h" % self.module)]
+        task = self.create_task('gen_ns3_module_header', self.env)
         task.set_inputs(all_headers_inputs)
         task.set_outputs(all_headers_outputs)
         task.module = self.module
diff --git a/utils/wscript b/utils/wscript
index dfbd84c1f..07e880b7c 100644
--- a/utils/wscript
+++ b/utils/wscript
@@ -2,18 +2,15 @@
 import os.path
 
 def configure(conf):
-    check = conf.create_pkgconfig_configurator()
-    check.name = 'goocanvas gthread-2.0'
-    check.uselib = 'MOBILITY_VISUALIZER'
-    check.mandatory = False
-    conf.env['ENABLE_MOBILITY_VISUALIZER'] = check.run()
+    conf.env['ENABLE_MOBILITY_VISUALIZER'] = conf.pkg_check_modules(
+        'MOBILITY_VISUALIZER', 'goocanvas gthread-2.0', mandatory=False)
     
 
 def build(bld):
-    env = bld.env_of_name('default')
+    env = bld.env
 
     unit_tests = bld.create_ns3_program('run-tests', ['common'])
-    unit_tests.inst_var  = 0 # do not install
+    unit_tests.install_path = None # do not install
     unit_tests.source = 'run-tests.cc'
     ## link unit test program with all ns3 modules
     unit_tests.uselib_local = 'ns3'
diff --git a/waf b/waf
index ece4755da..712934209 100755
Binary files a/waf and b/waf differ
diff --git a/wscript b/wscript
index 11ed03832..b80a9757b 100644
--- a/wscript
+++ b/wscript
@@ -1,24 +1,31 @@
 ## -*- Mode: python; py-indent-offset: 4; indent-tabs-mode: nil; coding: utf-8; -*-
+
+# python lib modules
 import sys
 import shutil
 import types
 import optparse
 import os.path
 
+# WAF modules
 import pproc as subprocess
-
-import Params
-import Object
+import Options
+import Logs
+import TaskGen
 import ccroot
 import Task
+import Utils
+import Build
+import Configure
 
+# local modules
 import wutils
 import regression
 
-Params.g_autoconfig = 1
+Options.autoconfig = 1
 
 # the following two variables are used by the target "waf dist"
-VERSION = file("VERSION").read().strip()
+VERSION = file("VERSION", "rt").read().strip()
 APPNAME = 'ns'
 
 wutils.VERSION = VERSION
@@ -36,7 +43,7 @@ def dist_hook():
     shutil.rmtree("nsc", True)
 
     if not os.path.exists("bindings/python/pybindgen"):
-        Params.fatal("Missing pybindgen checkout; run './waf configure --pybindgen-checkout' first.")
+        raise Utils.WafError("Missing pybindgen checkout; run './waf configure --pybindgen-checkout' first.")
 
     ## build the name of the traces subdirectory.  Will be something like
     ## ns-3-dev-ref-traces
@@ -44,7 +51,7 @@ def dist_hook():
     ## Create a tar.bz2 file with the traces
     traces_dir = os.path.join(regression.REGRESSION_DIR, traces_name)
     if not os.path.isdir(traces_dir):
-        Params.warning("Not creating traces archive: the %s directory does not exist" % traces_dir)
+        Logs.warn("Not creating traces archive: the %s directory does not exist" % traces_dir)
     else:
         traceball = traces_name + wutils.TRACEBALL_SUFFIX
         tar = tarfile.open(os.path.join("..", traceball), 'w:bz2')
@@ -160,19 +167,18 @@ def check_compilation_flag(conf, flag):
     flag: can be a string or a list of strings
     """
 
-    # Check for -Wno-error=deprecated-declarations
-    save_CXXFLAGS = list(conf.env['CXXFLAGS'])
-    conf.env.append_value('CXXFLAGS', flag)
-    e = conf.create_test_configurator()
-    e.mandatory = 0
-    e.code = '#include <stdio.h>\nint main() { return 0; }\n'
-    e.want_message = 0
-    ok = e.run()
-    conf.check_message_custom(flag, 'compilation flag support',
-                              (ok and 'yes' or 'no'))
+    env = conf.env.copy()
+    env.append_value('CXXFLAGS', flag)
+    try:
+        retval = conf.run_c_code(code='#include <stdio.h>\nint main() { return 0; }\n',
+                                 env=env, compile_filename='test.cc',
+                                 compile_mode='cxx',type='program', execute=False)
+    except Configure.ConfigurationError:
+        ok = False
+    else:
+        ok = (retval == 0)
+    conf.check_message_custom(flag, 'support', (ok and 'yes' or 'no'))
 
-    if not ok: # if it doesn't accept, remove it again
-        conf.env['CXXFLAGS'] = save_CXXFLAGS
     
 def report_optional_feature(conf, name, caption, was_enabled, reason_not_enabled):
     conf.env.append_value('NS3_OPTIONAL_FEATURES', (name, caption, was_enabled, reason_not_enabled))
@@ -184,12 +190,14 @@ def configure(conf):
     conf.report_optional_feature = types.MethodType(report_optional_feature, conf)
     conf.env['NS3_OPTIONAL_FEATURES'] = []
 
-    conf.env['NS3_BUILDDIR'] = conf.m_blddir
+    conf.env['NS3_BUILDDIR'] = conf.blddir
     conf.check_tool('compiler_cxx')
+    conf.check_tool('pkgconfig')
+    conf.check_tool('command')
 
     # create the second environment, set the variant and set its name
     variant_env = conf.env.copy()
-    debug_level = Params.g_options.debug_level.lower()
+    debug_level = Options.options.debug_level.lower()
     if debug_level == 'ultradebug':
         variant_name = 'debug'
     else:
@@ -197,12 +205,12 @@ def configure(conf):
 
     variant_env['INCLUDEDIR'] = os.path.join(variant_env['PREFIX'], 'include')
 
-    if Params.g_options.regression_traces is not None:
-        variant_env['REGRESSION_TRACES'] = os.path.join("..", Params.g_options.regression_traces)
+    if Options.options.regression_traces is not None:
+        variant_env['REGRESSION_TRACES'] = os.path.join("..", Options.options.regression_traces)
     else:
         variant_env['REGRESSION_TRACES'] = None
 
-    if Params.g_options.enable_gcov:
+    if Options.options.enable_gcov:
         variant_name += '-gcov'
         variant_env.append_value('CCFLAGS', '-fprofile-arcs')
         variant_env.append_value('CCFLAGS', '-ftest-coverage')
@@ -226,13 +234,13 @@ def configure(conf):
         check_compilation_flag(conf, '-Wno-error=deprecated-declarations')
 
         
-    if 'debug' in Params.g_options.debug_level.lower():
+    if 'debug' in Options.options.debug_level.lower():
         variant_env.append_value('CXXDEFINES', 'NS3_ASSERT_ENABLE')
         variant_env.append_value('CXXDEFINES', 'NS3_LOG_ENABLE')
 
     ## In optimized builds we still want debugging symbols, e.g. for
     ## profiling, and at least partially usable stack traces.
-    if ('optimized' in Params.g_options.debug_level.lower() 
+    if ('optimized' in Options.options.debug_level.lower() 
         and 'CXXFLAGS' not in os.environ):
         for flag in variant_env['CXXFLAGS_DEBUG']:
             ## this probably doesn't work for MSVC
@@ -240,7 +248,7 @@ def configure(conf):
                 variant_env.append_value('CXXFLAGS', flag)
 
     ## in optimized builds, replace -O2 with -O3
-    if 'optimized' in Params.g_options.debug_level.lower():
+    if 'optimized' in Options.options.debug_level.lower():
         lst = variant_env['CXXFLAGS']
         for i, flag in enumerate(lst):
             if flag == '-O2':
@@ -254,9 +262,9 @@ def configure(conf):
     conf.sub_config('utils')
     conf.sub_config('bindings/python')
 
-    if Params.g_options.enable_modules:
+    if Options.options.enable_modules:
         conf.env['NS3_ENABLED_MODULES'] = ['ns3-'+mod for mod in
-                                           Params.g_options.enable_modules.split(',')]
+                                           Options.options.enable_modules.split(',')]
 
     # we cannot run regression tests without diff
     conf.find_program('diff', var='DIFF')
@@ -280,9 +288,9 @@ def configure(conf):
 class SuidBuildTask(Task.TaskBase):
     """task that makes a binary Suid
     """
+    after = 'link'
     def __init__(self, bld, program):
         self.m_display = 'build-suid'
-        self.prio = 1000 # build after the rest of ns-3
         self.__program = program
         self.__env = bld.env ()
         super(SuidBuildTask, self).__init__()
@@ -291,29 +299,30 @@ class SuidBuildTask(Task.TaskBase):
         try:
             program_obj = wutils.find_program(self.__program.target, self.__env)
         except ValueError, ex:
-            Params.fatal(str(ex))
+            raise Utils.WafError(str(ex))
 
-        try:
-            program_node = program_obj.path.find_build(ccroot.get_target_name(program_obj))
-        except AttributeError:
-            Params.fatal("%s does not appear to be a program" % (self.__program.name,))
+        program_node = program_obj.path.find_or_declare(ccroot.get_target_name(program_obj))
+        #try:
+        #    program_node = program_obj.path.find_or_declare(ccroot.get_target_name(program_obj))
+        #except AttributeError:
+        #    raise Utils.WafError("%s does not appear to be a program" % (self.__program.name,))
 
         filename = program_node.abspath(self.__env)
         os.system ('sudo chown root ' + filename)
         os.system ('sudo chmod u+s ' + filename)
 
 def create_suid_program(bld, name):
-    program = bld.create_obj('cpp', 'program')
+    program = bld.new_task_gen('cxx', 'program')
     program.is_ns3_program = True
     program.module_deps = list()
     program.name = name
     program.target = name
-    if bld.env ()['SUDO'] and Params.g_options.enable_sudo:
-        SuidBuildTask (bld, program)
+    if bld.env['SUDO'] and Options.options.enable_sudo:
+        SuidBuildTask(bld, program)
     return program
 
 def create_ns3_program(bld, name, dependencies=('simulator',)):
-    program = bld.create_obj('cpp', 'program')
+    program = bld.new_task_gen('cxx', 'program')
     program.is_ns3_program = True
     program.name = name
     program.target = program.name
@@ -322,7 +331,7 @@ def create_ns3_program(bld, name, dependencies=('simulator',)):
     return program
 
 def add_scratch_programs(bld):
-    all_modules = [mod[len("ns3-"):] for mod in bld.env()['NS3_MODULES']]
+    all_modules = [mod[len("ns3-"):] for mod in bld.env['NS3_MODULES']]
     for filename in os.listdir("scratch"):
         if filename.startswith('.') or filename == 'CVS':
 	    continue
@@ -356,7 +365,7 @@ def _exec_command_interact_win32(s):
 
 
 def build(bld):
-    if Params.g_options.no_task_lines:
+    if Options.options.no_task_lines:
         import Runner
         def null_printout(s):
             pass
@@ -366,28 +375,30 @@ def build(bld):
         import Runner
         Runner.exec_command = _exec_command_interact_win32
 
-    Params.g_cwd_launch = Params.g_build.m_curdirnode.abspath()
+    Options.cwd_launch = bld.path.abspath()
     bld.create_ns3_program = types.MethodType(create_ns3_program, bld)
     bld.create_suid_program = types.MethodType(create_suid_program, bld)
+
+    # switch default variant to the one matching our debug level
     variant_name = bld.env_of_name('default')['NS3_ACTIVE_VARIANT']
     variant_env = bld.env_of_name(variant_name)
-    bld.m_allenvs['default'] = variant_env # switch to the active variant
+    bld.all_envs['default'] = variant_env
 
-    if Params.g_options.shell:
+    if Options.options.shell:
         run_shell()
         raise SystemExit(0)
 
-    if Params.g_options.doxygen:
+    if Options.options.doxygen:
         doxygen()
         raise SystemExit(0)
 
     check_shell()
 
-    if Params.g_options.doxygen:
+    if Options.options.doxygen:
         doxygen()
         raise SystemExit(0)
 
-    print "Entering directory `%s'" % os.path.join(Params.g_build.m_curdirnode.abspath(), 'build')
+    print "Entering directory `%s'" % os.path.join(bld.path.abspath(), 'build')
     # process subfolders from here
     bld.add_subdirs('src')
     bld.add_subdirs('samples utils examples')
@@ -397,13 +408,13 @@ def build(bld):
     ## if --enabled-modules option was given, we disable building the
     ## modules that were not enabled, and programs that depend on
     ## disabled modules.
-    env = bld.env()
+    env = bld.env
 
-    if Params.g_options.enable_modules:
-        Params.warning("the option --enable-modules is being applied to this build only;"
+    if Options.options.enable_modules:
+        Logs.warn("the option --enable-modules is being applied to this build only;"
                        " to make it permanent it needs to be given to waf configure.")
         env['NS3_ENABLED_MODULES'] = ['ns3-'+mod for mod in
-                                      Params.g_options.enable_modules.split(',')]
+                                      Options.options.enable_modules.split(',')]
 
     if env['NS3_ENABLED_MODULES']:
         modules = env['NS3_ENABLED_MODULES']
@@ -422,17 +433,17 @@ def build(bld):
                         changed = True
 
         ## remove objects that depend on modules not listed
-        for obj in list(Object.g_allobjs):
+        for obj in list(Build.bld.all_task_gen):
             if hasattr(obj, 'ns3_module_dependencies'):
                 for dep in obj.ns3_module_dependencies:
                     if dep not in modules:
-                        Object.g_allobjs.remove(obj)
+                        Build.bld.all_task_gen.remove(obj)
                         break
             if obj.name in env['NS3_MODULES'] and obj.name not in modules:
-                Object.g_allobjs.remove(obj)
+                Build.bld.all_task_gen.remove(obj)
 
     ## Create a single ns3 library containing all enabled modules
-    lib = bld.create_obj('cpp', 'shlib')
+    lib = bld.new_task_gen('cxx', 'shlib')
     lib.name = 'ns3'
     lib.target = 'ns3'
     if env['NS3_ENABLED_MODULES']:
@@ -445,25 +456,25 @@ def build(bld):
 
     bld.add_subdirs('bindings/python')
 
-    if Params.g_options.run:
+    if Options.options.run:
         # Check that the requested program name is valid
-        program_name, dummy_program_argv = wutils.get_run_program(Params.g_options.run, get_command_template())
+        program_name, dummy_program_argv = wutils.get_run_program(Options.options.run, get_command_template())
 
         # When --run'ing a program, tell WAF to only build that program,
         # nothing more; this greatly speeds up compilation when all you
         # want to do is run a test program.
-        if not Params.g_options.compile_targets:
-            Params.g_options.compile_targets = program_name
+        if not Options.options.compile_targets:
+            Options.options.compile_targets = program_name
 
 
 
 def get_command_template(*arguments):
-    if Params.g_options.valgrind:
-        if Params.g_options.command_template:
-            Params.fatal("Options --command-template and --valgrind are conflicting")
+    if Options.options.valgrind:
+        if Options.options.command_template:
+            raise Utils.WafError("Options --command-template and --valgrind are conflicting")
         cmd = "valgrind --leak-check=full %s"
     else:
-        cmd = Params.g_options.command_template or '%s'
+        cmd = Options.options.command_template or '%s'
     for arg in arguments:
         cmd = cmd + " " + arg
     return cmd
@@ -477,14 +488,14 @@ def shutdown():
     #ut.want_to_see_test_error = True
     #ut.run()
     #ut.print_results()
-    env = Params.g_build.env_of_name('default')
+    env = Build.bld.env
 
-    if Params.g_commands['check']:
+    if Options.commands['check']:
         _run_waf_check()
 
-    if Params.g_options.regression or Params.g_options.regression_generate:
+    if Options.options.regression or Options.options.regression_generate:
         if not env['DIFF']:
-            Params.fatal("Cannot run regression tests: the 'diff' program is not installed.")
+            raise Utils.WafError("Cannot run regression tests: the 'diff' program is not installed.")
 
         _dir = os.getcwd()
         os.chdir("regression")
@@ -498,20 +509,20 @@ def shutdown():
         if retval:
             sys.exit(retval)
 
-    if Params.g_options.lcov_report:
+    if Options.options.lcov_report:
         lcov_report()
 
-    if Params.g_options.run:
-        wutils.run_program(Params.g_options.run, get_command_template())
+    if Options.options.run:
+        wutils.run_program(Options.options.run, get_command_template())
         raise SystemExit(0)
 
-    if Params.g_options.pyrun:
-        wutils.run_python_program(Params.g_options.pyrun)
+    if Options.options.pyrun:
+        wutils.run_python_program(Options.options.pyrun)
         raise SystemExit(0)
 
 def _run_waf_check():
     ## generate the trace sources list docs
-    env = Params.g_build.env_of_name('default')
+    env = Build.bld.env
     proc_env = wutils.get_proc_env()
     try:
         program_obj = wutils.find_program('print-introspected-doxygen', env)
@@ -520,7 +531,7 @@ def _run_waf_check():
                        # --enable-modules=xxx
         pass
     else:
-        prog = program_obj.path.find_build(ccroot.get_target_name(program_obj)).abspath(env)
+        prog = program_obj.path.find_or_declare(ccroot.get_target_name(program_obj)).abspath(env)
         out = open(os.path.join('doc', 'introspected-doxygen.h'), 'w')
         if subprocess.Popen([prog], stdout=out, env=proc_env).wait():
             raise SystemExit(1)
@@ -541,7 +552,7 @@ def _run_waf_check():
 def check_shell():
     if 'NS3_MODULE_PATH' not in os.environ:
         return
-    env = Params.g_build.env_of_name('default')
+    env = Build.bld.env
     correct_modpath = os.pathsep.join(env['NS3_MODULE_PATH'])
     found_modpath = os.environ['NS3_MODULE_PATH']
     if found_modpath != correct_modpath:
@@ -554,7 +565,7 @@ def check_shell():
                "You should correct this situation before running any program.  Possible solutions:\n"
                "  1. Exit this shell, and start a new one\n"
                "  2. Run a new nested shell")
-        Params.fatal(msg)
+        raise Utils.WafError(msg)
 
 
 def run_shell():
@@ -563,12 +574,12 @@ def run_shell():
     else:
         shell = os.environ.get("SHELL", "/bin/sh")
 
-    env = Params.g_build.env_of_name('default')
+    env = Build.bld.env
     wutils.run_argv([shell], {'NS3_MODULE_PATH': os.pathsep.join(env['NS3_MODULE_PATH'])})
 
 def doxygen():
     if not os.path.exists('doc/introspected-doxygen.h'):
-        Params.warning("doc/introspected-doxygen.h does not exist; run waf check to generate it.")
+        Logs.warn("doc/introspected-doxygen.h does not exist; run waf check to generate it.")
 
     ## run doxygen
     doxygen_config = os.path.join('doc', 'doxygen.conf')
@@ -576,11 +587,11 @@ def doxygen():
         raise SystemExit(1)
 
 def lcov_report():
-    env = Params.g_build.env_of_name('default')
+    env = Build.bld.env
     variant_name = env['NS3_ACTIVE_VARIANT']
 
     if 'gcov' not in variant_name:
-        Params.fatal("project not configured for code coverage;"
+        raise Utils.WafError("project not configured for code coverage;"
                      " reconfigure with --enable-gcov")
 
     os.chdir(blddir)
@@ -618,7 +629,7 @@ def lcov_report():
 ## implementation that is more efficient.
 ##
 import Scripting
-from Scripting import g_dist_exts, g_excludes, BLDDIR
+from Scripting import dist_exts, excludes, BLDDIR
 import Utils
 import os
 
@@ -667,7 +678,7 @@ def copytree(src, dst, symlinks=False, excludes=(), build_dir=None):
                 if name.startswith('.') or name.startswith('++'):
                     to_remove = True
                 else:
-                    for x in g_dist_exts:
+                    for x in dist_exts:
                         if ends(x):
                             to_remove = True
                             break
@@ -707,7 +718,7 @@ def DistDir(appname, version):
     build_dir = getattr(Utils.g_module, BLDDIR, None)
 
     # Copy everything into the new folder
-    copytree('.', TMPFOLDER, excludes=g_excludes, build_dir=build_dir)
+    copytree('.', TMPFOLDER, excludes=excludes, build_dir=build_dir)
 
     # TODO undocumented hook
     dist_hook = getattr(Utils.g_module, 'dist_hook', None)
diff --git a/wutils.py b/wutils.py
index fe89dd579..1b0413692 100644
--- a/wutils.py
+++ b/wutils.py
@@ -1,15 +1,22 @@
 import os
 import os.path
-import Params
-import Object
 import sys
 import pproc as subprocess
 import shlex
+
+# WAF modules
 import ccroot
+import Options
+import Utils
+import Logs
+import TaskGen
+import Build
+
 
 # these are set from the main wscript file
 APPNAME=None
 VERSION=None
+
 #
 # The last part of the path name to use to find the regression traces tarball.
 # path will be APPNAME + '-' + VERSION + REGRESSION_SUFFIX + TRACEBALL_SUFFIX,
@@ -20,12 +27,12 @@ TRACEBALL_SUFFIX = ".tar.bz2"
 
 
 def get_command_template(*arguments):
-    if Params.g_options.valgrind:
-        if Params.g_options.command_template:
-            Params.fatal("Options --command-template and --valgrind are conflicting")
+    if Options.options.valgrind:
+        if Options.options.command_template:
+            raise Utils.WafError("Options --command-template and --valgrind are conflicting")
         cmd = "valgrind --leak-check=full %s"
     else:
-        cmd = Params.g_options.command_template or '%s'
+        cmd = Options.options.command_template or '%s'
     for arg in arguments:
         cmd = cmd + " " + arg
     return cmd
@@ -33,9 +40,9 @@ def get_command_template(*arguments):
 
 
 def find_program(program_name, env):
-    launch_dir = os.path.abspath(Params.g_cwd_launch)
+    launch_dir = os.path.abspath(Options.cwd_launch)
     found_programs = []
-    for obj in Object.g_allobjs:
+    for obj in Build.bld.all_task_gen:
         if not getattr(obj, 'is_ns3_program', False):
             continue
 
@@ -51,7 +58,7 @@ def find_program(program_name, env):
                      % (program_name, found_programs))
 
 def get_proc_env(os_env=None):
-    env = Params.g_build.env_of_name('default')
+    env = Build.bld.env
     if sys.platform == 'linux2':
         pathvar = 'LD_LIBRARY_PATH'
     elif sys.platform == 'darwin':
@@ -63,7 +70,7 @@ def get_proc_env(os_env=None):
     elif sys.platform.startswith('freebsd'):
         pathvar = 'LD_LIBRARY_PATH'
     else:
-        Params.warning(("Don't know how to configure "
+        Logs.warn(("Don't know how to configure "
                         "dynamic library path for the platform %r;"
                         " assuming it's LD_LIBRARY_PATH.") % (sys.platform,))
         pathvar = 'LD_LIBRARY_PATH'        
@@ -78,7 +85,7 @@ def get_proc_env(os_env=None):
         else:
             proc_env[pathvar] = os.pathsep.join(list(env['NS3_MODULE_PATH']))
 
-    pymoddir = Params.g_build.m_curdirnode.find_dir('bindings/python').abspath(env)
+    pymoddir = Build.bld.path.find_dir('bindings/python').abspath(env)
     if 'PYTHONPATH' in proc_env:
         proc_env['PYTHONPATH'] = os.pathsep.join([pymoddir] + [proc_env['PYTHONPATH']])
     else:
@@ -88,10 +95,10 @@ def get_proc_env(os_env=None):
 
 def run_argv(argv, os_env=None):
     proc_env = get_proc_env(os_env)
-    #env = Params.g_build.env_of_name('default')
+    #env = Build.bld.env
     retval = subprocess.Popen(argv, env=proc_env).wait()
     if retval:
-        Params.fatal("Command %s exited with code %i" % (argv, retval))
+        raise Utils.WafError("Command %s exited with code %i" % (argv, retval))
     return retval
 
 def get_run_program(program_string, command_template=None):
@@ -100,7 +107,7 @@ def get_run_program(program_string, command_template=None):
     run_program(program_string, command_template).
     """
     #print "get_run_program_argv(program_string=%r, command_template=%r)" % (program_string, command_template)
-    env = Params.g_build.env_of_name('default')
+    env = Build.bld.env
 
     if command_template in (None, '%s'):
         argv = shlex.split(program_string)
@@ -109,12 +116,13 @@ def get_run_program(program_string, command_template=None):
         try:
             program_obj = find_program(program_name, env)
         except ValueError, ex:
-            Params.fatal(str(ex))
+            raise Utils.WafError(str(ex))
 
-        try:
-            program_node = program_obj.path.find_build(ccroot.get_target_name(program_obj))
-        except AttributeError:
-            Params.fatal("%s does not appear to be a program" % (program_name,))
+        program_node = program_obj.path.find_or_declare(ccroot.get_target_name(program_obj))
+        #try:
+        #    program_node = program_obj.path.find_build(ccroot.get_target_name(program_obj))
+        #except AttributeError:
+        #    raise Utils.WafError("%s does not appear to be a program" % (program_name,))
 
         execvec = [program_node.abspath(env)] + argv[1:]
 
@@ -124,11 +132,13 @@ def get_run_program(program_string, command_template=None):
         try:
             program_obj = find_program(program_name, env)
         except ValueError, ex:
-            Params.fatal(str(ex))
-        try:
-            program_node = program_obj.path.find_build(ccroot.get_target_name(program_obj))
-        except AttributeError:
-            Params.fatal("%s does not appear to be a program" % (program_name,))
+            raise Utils.WafError(str(ex))
+
+        program_node = program_obj.path.find_or_declare(ccroot.get_target_name(program_obj))
+        #try:
+        #    program_node = program_obj.path.find_build(ccroot.get_target_name(program_obj))
+        #except AttributeError:
+        #    raise Utils.WafError("%s does not appear to be a program" % (program_name,))
 
         execvec = shlex.split(command_template % (program_node.abspath(env),))
     return program_name, execvec
@@ -142,10 +152,10 @@ def run_program(program_string, command_template=None):
     """
     dummy_program_name, execvec = get_run_program(program_string, command_template)
     former_cwd = os.getcwd()
-    if (Params.g_options.cwd_launch):
-        os.chdir(Params.g_options.cwd_launch)
+    if (Options.options.cwd_launch):
+        os.chdir(Options.options.cwd_launch)
     else:
-        os.chdir(Params.g_cwd_launch)
+        os.chdir(Options.cwd_launch)
     try:
         retval = run_argv(execvec)
     finally:
@@ -156,14 +166,14 @@ def run_program(program_string, command_template=None):
 
 
 def run_python_program(program_string):
-    env = Params.g_build.env_of_name('default')
+    env = Build.bld.env
     execvec = shlex.split(program_string)
 
     former_cwd = os.getcwd()
-    if (Params.g_options.cwd_launch):
-        os.chdir(Params.g_options.cwd_launch)
+    if (Options.options.cwd_launch):
+        os.chdir(Options.options.cwd_launch)
     else:
-        os.chdir(Params.g_cwd_launch)
+        os.chdir(Options.cwd_launch)
     try:
         retval = run_argv([env['PYTHON']] + execvec)
     finally: