There are several open source options for nice 3D graphics extensions, but they use .NET 3.0. I'm particularly interested in www.dislin.com, free despite the .com
.NET 3 is backwards compatible w/ 2 so this move would not break anything and everyone should have .NET unless they are still running XP which is no longer supported.
Excellent news, thank you. (Documents still say .NET 2)
.NET 2 is the basic requirement to run SMath; this means that you can run it just if you have the .NET Framework 2/3/3.5 installed in your system, and doesn't work if you have previous versions installed (1/1.1). Frameworks 2/3/3.5 are all based on the same CLR, so you can develop plugins targeted to any of these versions.