[jeremiep]

There's the dub package manager for D. http://code.dlang.org/

I don't think I'd want web and mail servers straight into the standard library out of the box. Those are way too specific. For example, there's already vibe.d for web servers and its doing an excellent job. They even have compile-time HTML templates!

As for IDEs, on Windows I've recently used VisualD and it did a good job. It's not yet as complete as the C# integration of Visual Studio (especially when taking ReSharper into account), but it definitely feels like an IDE. It already has improved hugely over when I last used it last year.