If you want to build ns3, you need to install scons (see
http://www.scons.org). scons takes care of building
the whole source tree using your system compiler. scons
0.91.1 and 0.91.96 have been tested and are known to 
work on linux FC5, Mac os X and MinGW.

To start a build, you can just type 'scons' which
will generate a debug shared build by default, located
in the directory 'build-dir/dbg-shared/bin' and
'build-dir/dbg-shared/lib'.

1) Options
----------

- verbose: if you have install scons 0.91.96, the default
  build output is terse. To get a more verbose output, you
  need to set the 'verbose' variable to 'y'.

Example:
scons verbose=y

2) Targets
----------

- doc: build the doxygen documentation.
Example:
scons doc

- dbg-shared: a debug build using shared libraries.
  The files are built in 'build-dir/dbg-shared/'.
Example:
scons dbg-shared

- dbg-static: a debug build using static libraries
  The files are built in 'build-dir/dbg-static/'.
Example:
scons dbg-static

- opt-shared: an optimized build using shared libraries.
  The files are built in 'build-dir/opt-shared/'.
Example:
scons opt-shared

- opt-static: an optimized build using static libraries.
  The files are built in 'build-dir/opt-static/'.
Example:
scons opt-static

- dbg: an alias for dbg-shared
Example:
scons dbg

- opt: an alias for opt-shared
Example:
scons opt

- all: alias for dbg-shared, dbg-static, opt-shared 
  and opt-static
Example:
scons all

- dist: generate a release tarball and zipfile from the 
  source tree. The tarball and zipfile name are generated
  according to the version number stored in the SConstruct
  file.
Example in SConstruct:
ns3 = Ns3 ()
ns3.name = 'foo'
ns3.version = '0.0.10'
Example command:
scons dist
Example output:
foo-0.0.10.tar.gz
foo-0.0.10.zip

- distcheck: generate a release tarball and zipfile and 
  attempt to run the 'all' target for the release tarball.
Example:
scons distcheck