Basic Procedures for Cyclic, Hamming, Binary Reed-Muller, BCH, Golay codes: Maple procedures for standard operations with various families of codes.
Error Correcting Codes Page: Programs written in C/C++ and Matlab that implement encoding and decoding routines of popular error correcting codes. Collected by Robert Morelos-Zaragoza.
Error-Correcting Codes in MAPLE: Basic procedures for Cyclic, Hamming, Binary Reed-Muller, BCH and Golay codes.
Low-Density Parity Check Binary Codes: MATLAB software by Igor Kozintsev.
PAFF: Package for Algebraic Function Fields in one variable. Construction of geometric Goppa codes (also called algebraic geometric codes or AG-codes). Source code is available.