What the hell is squeak?

Latest interest: Squeak. I want to say more but I cannot. At least not until I meet someone who can actually tell me what it is. Running it seems to show that it is a special environment for coding. Think of it as an uber-environment where objects are created and instantiated on the fly. All using Smalltalk.

Actually my interest was piqed by an article about Alan Kay on the recent ACM Queue.