I know, there are more noble relatives, as Mixxx or Virtual DJ, but i have a sympathy for this freebie little guy (free software for Windows, MacOSX, and iOS).
He is very light and doesn’t need the large resources requested by other dj software, but it has everything you need to start dj as a pro, including Loops, Hotcues, and Freeze Mode.
Traktor DJ 2 does not have a direct interface to Shoutcast, but it works well with Butt. Put some tracks in Traktor and start broadcasting with Butt, it is all that you need to dj on Second Life without having to worry about whether or not the computer will make it (if you don’t know how to use Butt for streaming, you missed our guide “How play music in Second Life: the definitive guide“. Take a look).
Pretty job by Native Instruments. If you own also a Traktor Kontrol S2 fun is guaranteed.