There’s updated documentation for bam.
Part of the difficulty in describing BAM is where to begin. Although the API itself is pretty small: 3 main classes and basically 10 commonly-used methods, the number of use cases is large.
So the current documentation primarily focuses on messaging, i.e. viewing BAM as a replacement for JMS, showing how to configure a queuing service and describing several built-in services. The idea is to show the simple, useful BAM cases, rather than getting too involved in the more complicated applications.
Other applications like IM, multi-user chat, pub-sub, and interactive applications are only alluded to.