There have been some great weblog posts recently about the internals of Tamarin. If you're interested in more details about Tamarin, try the following:
For the brave there is an implementation of the Tamarin engine that runs as a scripting engine within Internet Explorer. Called 'Screaming Monkey' it is actually working and an alpha release is available. Screaming Monkey is based on the Tamarin Central engine, rather than the Tamarin Tracing engine.