Works on: Windows, Mac, Linux
UltraMixer2 is a very interesting free DJ software. It lets you mix up your songs, and add all the DJ effects. UltraMixer2 enables you to mix digital music in various formats such as MP3, WMA, AAC, OGG, WAV or CDs in real time. It packs in all the professional features, and still is very easy to use.
Using UltraMixer2, you can play like a professional DJ. Instead of two turntables, you get two digital sound players. Each sound player comes with its own equalizer and set of tools so that you can mix the music properly.
UltraMixer is available for free download for Windows, Mac, as well as Linux.
UltraMixer2 would make it a lot of fun for you to play songs and music at parties, or just for yourself. Free version of UltraMixer2 can be used for private non-public use.
Download links, and Video Tutorial at the end.