The C#/VB async feature looks like a variation of the F# feature and seems to derive from it. The C# team work pretty closely with the F# team. There is a good

The C#/VB async feature looks like a variation of the F# feature and seems to derive from it. The C# team work pretty closely with the F# team. There is a good comparison here of the C# and F# features here: http://tomasp.net/blog/csharp-fsharp-async-intro.aspx http://tomasp.net/blog/csharp-fsharp-async-intro.aspx. There's a paper on the F# asynchronous model mentioned at the end.