What are some alternatives?
When comparing Qtractor and Mixxx, you can also consider the following products
Ardour - Record, edit, and mix on Linux, Mac OS X, and Windows.
Mixmeister - Create custom party mixes, burn CDs, or add special effects to MP3s with this line of DJ software for the novice and pro. Offers free trials and user community.
LMMS - Make music with a free, cross-platform tool
Deckadance - Deckadance is a DJ mixing application that works either as a standalone program OR as a VSTi inside...
FL Studio - Image-Line's FL Studio, now on it's 12th version, is a well-known music production suite and the most popular beat processor on the market, due no doubt to its longevity. Read more about FL Studio.
Cross DJ - Mix, scratch, sample, record: rock great parties with top-DJ features.