Rolf Bjarne's VB 8 compiler is now self-hosting on Mono. This represents a major milestone for both the Mono team and the VB language.
For the Mono team, having their own VB compiler is essential for ASP.Net support. Unlike other VB-based applications which can be pre-compiled on a Windows box, ASP.Net has to be able to compile VB code found in ASPX files at runtime.
This is also the first widely available Visual Basic compiler actually written in Visual Basic. The VB compilers created by Microsoft are all written in C++.
A new version of the VB Runtime written entirely in Visual Basic is also available. In the past Mono needed a combination of ILASM and Perl hacks to construct the runtime.
The VB Runtime is a core library for VB applications, much like the C runtime. It contains most of the functions unique to Visual Basic, though it can be called from any CLS compliant language. Being a library rather than an environment, it should not be confused with virtual machines like the Common Language Runtime (CLR).