Smasher is an audio editor that will satisfy the needs of DJs. Smasher lets you create loops from WAV, MP3, FLAC or AIFF files quickly, without needing a sequencer. It also offers all types of effects, like distortions, reverb, fade in/fade out, etc, with the advantage that each effect has parameters you can modify.
The Smasher interface shows two tables to edit the loops. One of them works as a sequencer and the other works on the effects. All the projects can be saved in WAV.
Smasher is a free, open source program.