Clementine - Clementine is a cross-platform free and open source music player and library organizer based on...
Mixed in Key - Mixed In Key is award-winning DJ software that gives you the #1 technique of the world's best...
KDE Elisa - Elisa is a music player by the KDE community to be simple and nice to use.
KeyFinder - Key estimation software for DJs
KDE JuK Media Player - JuK is a music player and music manager. It help you maintain your songs and modify their metadata tags.
Tunebat - A browser based song key and bpm database. Supplies compatible songs for harmonic mixing.