Impulse Tracker is one of the most popular and most advanced trackers for the MS-DOS system. Starting out as an enhanced clone of Scream Tracker 3, it mostly copied Scream Tracker's look and feel, but also brought over many new features from FastTracker 2 such as multi-sampled instruments and envelopes. In addition, Impulse Tracker features "New Note Actions" to have more than one note playing on a single tracker channel, MIDI input/output and, starting with version 2.14, resonant filters for samples. Impulse Tracker supports a wide variety of sound cards, resonant filters are only available for some of them, though, and require at least an MMX CPU (except when using the WAV writer). Although free software, the WAV writer did cost money. A commercial license (200 USD) was also available.
The final update (v2.14 patch #5) appeared on April 8, 1999.
On February 16, 2014, Jeffrey Lim announced the release of Impulse Tracker's complete assembly source code as part of its 20 year anniversary. The first part of the source code was released on October 19th, 2014, on Bitbucket, and on December 25, 2014, the missing parts (sound drivers) were added and the code was officially released under the BSD license.