Just I.M.'d airlynx this message and figured you guys could use the information:

Realism Emulation System is completely free to download and use because it uses the resources of many outside free 3D programs. Rather than being one single program, it's a collaboration of many different ones that all work particularly well together. The Postwork Edition (v0.5) can be found at http://www.angelfire.com/art2/reaemusys. Documentation can also be found there. I'm still (slowly, yes, but surely...) developing the Full Edition and when it's done it too will be available free of charge.