Mainsoft has released a preview of Grasshopper 2.0 that is compatible with Visual Studio 2005. Grasshopper allows Visual Studio developers to cross-compile IL into Java bytecode. Developers can then run their applications on a J2EE/Tomcat stack.
While Mainsoft has written its own core library (mscorlib) that works in conjunction with its cross-compiler, it relies on the Mono project for most of the .Net class library.
The current release version of Grasshopper is free on the Tomcat platform. If you want to run it on IBM WebShere, BEA Weblogic, or JBoss, a license for their enterprise offering, Visual WinMain for J2EE, will be needed.