Lambda the Ultimate

I'm looking for langauge theory, semantics books/resources that are good for self study and one I've found is:

Semantics with Applications: An Appetizer (Undergraduate Topics in Computer Science)

This book is pretty new (March 2007). Reading the first few pages of the first chapter looks like the authors start off at a reasonable pace. The thing that typically trips me up with resources I find online is the level of Maths. Specifically, the symbols used aren't symbols I'm used to seeing in something like calculus or real analysis.

Has anyone looked over this book? Thoughts, impressions?

My new laptop has one of those multi-core CPUs. And, as Herb Sutter suggests I want to start doing some serious concurrent programming with Scheme.

Since I'm relatively new to Scheme, I decided to ask the LtU experts about effective/real world ways to fully exploit those two CPU cores with Scheme. Here's what I come with after a little research:

• Termite is an Erlang-like distributed programming system written in Scheme. It includes a parallel map and different message-passing mechanisms. This looks pretty cool.
• Kali Scheme (abandoned?) is a distributed implementation of Scheme
• MultiLisp is a Scheme implementation with some special constructs for easy parallelization. Seems to me to be a little bit outdated
• Multiple processes on multiple cores is on the wishlist of Gambit Scheme

So here're my questions to the LtU Scheme experts:

• What is your preferred way to exploit multicores/multiprocessors from Scheme?
• Do you know of any other Scheme implementations that ease concurrent programming? Any libraries?