Mixxx

About

Mixxx integrates the tools DJs need to perform creative live mixes with digital music files, and it can support both new DJs with just a laptop and experienced turntablists. BPM and musical key detection help you find your next track from your library, and Sync Lock matches the tempo and beats of four songs for seamless mixing.

Mixxx includes built-in mappings for DJ controller hardware for hands-on control of its features, and its programmable mapping system lets you customize your workflow and add support for any MIDI or HID device. You can add sound effects to tracks, chain multiple effects together, and use turntables with timecode vinyl records to control playback and scratch your digital music files. Vinyl passthrough mode lets you mix music vinyls into your set.

Mixxx is free open-source software, developed by an international community of DJs, programmers, and artists rather than a company. The site notes it is free as in freedom and price, and that anyone can contribute by reporting bugs, suggesting features, making controller mappings, fixing bugs, or helping with translations. It is also described as the #1 Top Free Mac App Worldwide on the Mac App Store.