The CMU-Cambridge Statistical Language Modelling Toolkit is a longstanding set of Unix tools offered by Carnegie Mellon University and Cambridge University. It includes functions for word frequency, n-grams, vocabulary and words marked as 'context cues'. Version 1 was written by Roni Rosenfel and released in 1994.

SRILM (SRI Language Modelling Toolkit) is a toolkit for language modelling first developed in the 1990s and still in active development. It has applications in speech recognition, statistical tagging, segmentation and machine translation. The toolkit is available for Windows and UNIX, and users have developed a variety of extensions for it.