We recently opened up a new ASP.NET CodePlex Project that we will be using to provide previews (with buildable source code) for several upcoming ASP.NET features and releases.

Last month we used it to publish the first drop of the ASP.NET MVC source code. This first drop included the source for the ASP.NET MVC Preview 2 release that we shipped at MIX, along with Visual Studio project files to enable you to patch and build it yourself.

A few hours ago we published a refresh of the ASP.NET MVC source code on the site. This source refresh is not an official new ASP.NET MVC preview release - instead it is an interim drop that provides a look at the current state of the source tree. We will ship the official "ASP.NET MVC Preview 3" release in a few weeks after we finish up some more work (more features and tweaks to existing ones, better VS tool integration, VS express edition support, documentation, etc). If you are someone who wants a hassle-free installation of ASP.NET MVC to use that ships with documentation and full tool support you'll probably want to wait for this official preview release. If you are someone who wants a chance to see an early "preview of the preview" and have the opportunity to start using and giving feedback on some of the features immediately, today's source refresh is probably interesting to look at.