Quote - Maybe not fully ethical, but definitely fully legal: I used the 30 day trial version of VMWare Workstation to create a series of virtual machines, and now I use VMWare Player (free) to run them.
The pricey stuff from VMWare is mainly their ESX server line, brilliant software, but not what I need for development.
THere's only one major caveat that I found: graphics acceleration. Virtual machines running in VMWare don't benenfit from hardware accelerated graphics. No OpenGL, no DirectX. That might be a major problem.

But that is VMWare. I don't know how VirtualBox or other virtualization software handle OpenGL.

I don't think VirtualBox supports the 3d accelerators either, haven't done much testing but I'd be suprised if it did, most virtual machines don't.  But mostly I'll be using it for development purposes so when the time comes to make linux packages for testing I can always setup a full blown version and dual boot.

For right now though I'll be concentrating on the Windows version first, but coding in a Linux environment.  Might seem a bit strange, but there are so many great development packages for Linux and since I really want this to be cross-platform, it seemed the way to go.  I'll work on getting a compiled linux version out once I get the Windows version running the way I want.  As long as I stick to cross platform libs it shouldn't present a problem I don't think.

I've been giving some thought to collision detection, I think that's another one to add to the list of things you can schedule for either batch processing or distributed computing.

Basically what I'd like to be able to do is have a "batch processing window" where you can setup a lot of the more system intense features to run unattended on a schedule on your own pc, in background on other systems in your own network, or in background via a distributed computer network via the internet.

Other things you'll be able to batch process on my list include - renders, animations, dynamic cloth & hair, etc.

Right now I'm considering the best way to code the module/plugins interface, making the app very extensible without overburdening the GUI itself.  More thought needed there, but I'm working on it :)

-Never fear, RenderDog is near!  Oh wait, is that a chew toy?  Yup. ok, nevermind.. go back to fearing...