Products of visual3d.net
Multimedia \ Misc. Graphics
DotNet3D is an open API and foundation library for implementation by .NET-based 3D engines that allows usage with the Visual3D.NET (www.visual3d.net) platform and Visual3D Architect runtime development environment. DotNet3D 1.0 License - GNU Library or Lesser General Public License (LGPL).
Freeware download of DotNet3D 1.0, size
Development \ Misc. Dev. Tools
The first 3D game engine built in C# for .NET, predecessor to the Visual3D Game Engine (http://www.visual3d.net/game-engine), an All-in-One Game Development Tool for Next-Gen 3D Games, MMOs, Simulations and Virtual Worlds powered by Microsoft XNA..
Freeware download of RealmForge (now Visual3D Game Engine) 0.6.2, size