As of 2015, some good free music mixing programs are Mixxx, Zulu DJ and Cross DJ Free. Mixxx is available for Windows, Mac OSX and Ubuntu, while Zulu DJ and Cross DJ Free are available for Windows and Mac OSX.
Mixxx can integrate with iTunes and allows users to use their playlists and songs from their iTunes library. It also sync the tempo of songs automatically and supports audio formats including MP3, OGG and FLAC. Zulu DJ allows users to apply effects in real-time and supports common audio formats, such as MP3 and WAV. It also allows users to record and save their mixes into a file. Cross DJ Free offers two decks with mixer and iOS remote support.