I'm coming from the open source world, and interested in giving ASP.NET a spin. But I'm having a little trouble separating the tools from the platform itself in regards to the licensing. I've downloaded Visual Web Developer 2008 Express, but not sure how different this is from one of the full-featured Visual Studio licenses -- and whether or not my Express license will prevent me from using all the features of ASP.NET.

Is a Visual Studio license just an IDE, or does it include pieces of .NET not available to the Express license? What about the other tools like IIS and SQL Server?

Thanks.