Tapas Kanungo HMM software
Daniel Dementhon HMM software
Nikolai Shokirev HMM software
The General HMM library (ghmm)
Hidden Markov Model (HMM) Toolbox for Matlab by Kevin Murphy
Java HMM library (jhmm)
The modhmm package by Hakan Viklund
An HMM classifier in C#
HMMs in Perl
The libhmm package
The myHMM package
HMMs in C++
Mauro Delorenzi's MAMOT HMM software
HMMs in VB6
HMMs in python (pyhmm)
Piero Fariselli's PHMM