Enterprise Integration Patterns book
EIP book (Hohpe and Woolf) I think is a must-read for any OSS professional who is closely working with message processing like JMS, Kafka, etc or RPC (like CORBA).
Many enterprise integration problems, and their solutions are quite similar. Them are cataloged in the book and also thought behind each pattern (the desicions made, possible variants and customizations). Curiously in the past I had reinvented the patterns like: Resequencer and Splitter. So it was really pleasure for me to see such systematic view on the message passing.
If you haven’t read it, I encourage you to do so. The enterprise integration patterns, or EIPs, are helpful not only because they provide a proven solution for a given problem, but also because they help define and communicate the problem itself. Patterns have known semantics, which makes communicating problems much easier.