GAUSS Source Code Archive at American Univ.
This library is devoted to GAUSS programs. Be careful to read the
file titled "READ ME FIRST" describing the conditions and terms of
programs in it. In particular, it is for public, non-commercial
code, the code should be clearly attributed, and documented. This
file contains details on how to submit code to the library.
Besides listing code stored here, it also lists many other site
with GAUSS code.
http://gurukul.ucc.american.edu/econ/gaussres/GAUSSIDX.HTM