This week's book giveaway is in the Reactive Progamming forum. We're giving away four copies of Reactive Streams in Java: Concurrency with RxJava, Reactor, and Akka Streams and have Adam Davis on-line! See this thread for details.
Safari support for P & S is extremely good, because Thomas Fuchs and a lot of the Prototype/Rails crowd are Mac users. They do run the regression tests across a range of other browsers too, including IE.