You'll need to go to the Don't Crack website, put it in your cart. Its just a go to for me because not only does it have many great sounds, but with layering and such, you can really make it work! I can tell you from long experience that Xpand2 is easy to use, and, frankly, I find a reason to use it in about 80% of my work. Put this in Reason Combinator, and you can go crazy with sound design with this one. However, you can combine up to 4 sounds in it, each on its own MIDI channel if you wish, OR, just stack them for a nice full sound.

You can do some editing to fit your needs, but not load your own samples or anything like that. In any case, Xpand2 comes with some 2500 built in sounds. It appears from the description at Don't Crack, that you can upgrade to the full IEP for 50% off, so around $75 U.S. The IEP includes 7 of their VI's, including Structure (a powerful, flexible, easy to use, sample VI), Transfuser, a very nice groove machine with tons of control, Strike - very dynamic virtual drums, Loom, additive synth, Velvet (great EP sounds), Hybrid3 - easy to use, highly programmable synth, and Vacuum Pro - nice analog emulation VI. It appears that Air is letting Xpand2 go for free, in the hopes that you'll take advantage of the upgrade offer to get their full Instrument Expansion Pack (IEP). For a limited time, you can get Xpand2 from Air Instruments Free from the Don't Crack website. A friend of mine just posted this on the Pro Tools User forum.

How to download air xpand 2 vst