Impulse Tracker is a multi-track digital sound tracker (music sequencer). It was one of the last tracker programs for the DOS platform. It was authored by Jeffrey "Pulse" Lim, and example music was provided by Jeffrey Lim and Chris Jarvis. The first released version is from year 1995 and the last version, v2.14 Patch #5, was released April 8, 1999. On February 16, 2014, Jeffrey Lim announced that he would release the complete source code of Impulse Tracker as part of its 20 year anniversary.