I downloaded the 3ds Max 9 trial, it should be fully functional (for 30 days) with SDK to try to develop plugins for it. The SDK documentation says that Visual Studio 2005 .NET is needed... I'm gonna have a look on the 3DXI API, hopefully it's not as bad as the full API.

But if VS is really needed, then I'm screwed. I'm not gonna buy any VS crap just to build one plugin... :evil: