Very much enjoyed Joe Duffy and Joel Pobar’s session on “Build a compiler for managed code in less than an hour.” Basically, they stepped through the classic compiler stages (scanner, parser, code gen), but then went into how, in the .NET world, the System.Reflection.Emit libraries work. It might have been a little too ambitious in scope – if you carefully go over “what a scanner is,” then you might not even mention type coercion or autoboxing half-an-hour later. But it was a very well-attended session, they had good energy, and I think it was probably really good for many, many people. Heck, I’ve never seen all the .NET pieces in a single, easy-to-digest place before.