Bookpool is running a 50% sale for books from Apress and FriendsOfEd.
It's probably a good chance to snatch up some of their latest open source books. I also noticed a lot of new Rails books that are scheduled to be released later this year or earlier next year are on sale too.
Apress had impressed me lately with their timely publish of books on cutting edge web technologies and their focus in the open source arena. Also most of their books tend to be practical and easy to read, but the downside is that the contents are likely to become out dated soon, though it has a lot to do with the fast changing of the targeted technology topics. One of my old favorite, O'Reilly, had gradually become the opposite, where their coverage of new technologies tend to arrive some what late(just look at their book publishing dates on Ruby and Ruby on Rails relative to other publishers), but I have to admit their books' contents quality is still top notch and I always turn to their books for references and ones will be kept in my library in longest time.