GAC in CLR 2.0
Richard does a great series of 4 posts on the Global Assembly Cache (GAC) in CLR 2.0..more than you need to know for sure!
The Wonders of the Whidbey GAC -- Part I: Processor Architecture
The Wonders of the Whidbey GAC -- Part II: Interop with the Everett GAC
The Wonders of the Whidbey GAC -- Part IV: Shipping Everett and Whidbey Versions of the Same Code
Enjoy!