It's a development engine of sorts to create instruments, effects, and midi generators from basic building blocks, with a huge user library full of devices other people have built. It's essentially 3,000+ instruments, effects, and weird tools, and the modular environment to create your own, should you have the desire. It is definitely a epic repository for weird glitchy tools and experimental devices.
Last edited by penguinoid; 02-26-2012 at 08:28 AM..
Native Instruments offers free "Player Versions" of their products here: [Only registered and activated users can see links. Click here to register] They're fairly basic compared to what the full retail versions can do, but the software is still capable of creating some amazing sounds. You can always add synths such as Razor for extra money if you would like to explore N.I. software before making a large investment. But really, people always suggest N.I. products because they are really that good. Although other suggestions made here are also worth checking out.