"Concurrent Basic extends Visual Basic with stylish asynchronous concurrency constructs derived from the join calculus. Our design advances earlier MSRC work on Polyphonic C#, Comega and the Joins Library. Unlike its C# based predecessors, CB adopts a simple event-like syntax familiar to VB programmers, allows one to declare generic concurrency abstractions and provides more natural support for inheritance. CB also offers open extensibility based on custom attributes." Code Sample: Module Buffer   Public Asynchronous Put(ByVal s As String)   Public Synchronous Take() As String   Private Function CaseTakeAndPut(ByVal s As String) As String  When Take, Put      Return s   End Function End Module   OK. Sounds great. There are new keywords, Asynchronous and Synchronous. Conceptually, these are easy enough to understand. How do they work, exactly? What's the thinking behind the current design? Why was VB.NET chosen as the language to extend? Wouldn't any CLI language suffice? Who thought this up, anyway? What's the thinking behind the thinking? Enter C9 celebrity host Erik Meijer, who leads yet another great conversation with fellow software experts Claudio Russo (MSR Researcher and co-creator of Concurrent Basic) and Lucian Wischik (software developer and current VB.NET Czar). Obviously, we've been focusing a lot of attention of Concurrency and Parallelism over the past few years. We talk about the library versus language approach quite a bit. In this case, concurrency constructs have been baked into the language to form a different variant of VB, CB (Concurrent Basic). CB is a research project and therefore a research language. It has no ship vehicle and is not available for trial at this point. Microsoft makes no committment to shipping VB with these concurrency constructs built in. CB is a research language.  CB is being shown in action at this year's MSR TechFest. Be sure to check out Laura's coverage of TechFest 2009.