The Macintosh version of SWIG is now a separate distribution (both in
source and binary form).  Building it from source is tricky and
requires Tcl 8.0, MacGoodies, and Code Warrior 10.  If at all
possible, look for the binary distribution instead.

The Macintosh port is a work in progress.  Don't expect it work with
everything, but constributions to the effort are always welcome!