Source code for lots of code-related functions: including "code6" for making Gallager codes; "mncN" and "gallager" for sum-product decoding and "fe" for decoding using variational free energy minimization (not the best decoder; sum-product is better) Before making executables, you may need to create some directories in both . and ./ansi thus:
mkdir bin$ARC; cd bin$ARC ; ln -s ../_Makefile Makefile ; cd .. OR for example: mkdir bini386; cd bini386; ln -s ../_Makefile Makefile ; cd ..
[The main programs I use in my work on Gallager codes are code6 and gallager.]
The software is provided under the GNU General Public License.