There is only one file type that uses the .KIN extension:
Kinetic Music Project
Audio project file created by Kinetic, an application for creating electronic music; stores audio loops and instrument patches on a multitrack timeline; can be exported to common audio formats (e.g., .WAV or .MP3) and played in a standard audio player.
NOTE: Cakewalk Kinetic is no longer developed and was succeeded by Cakewalk SONAR.
Updated: September 3, 2014