I'm disappointed in the vi/vim part of "Regular Expression Pocket Reference" (new from ORA). It's not very thorough. It does, at least, mention vim and list some of its more common bits of syntax, but it doesn't go far enough. It doesn't provide a full summary of the vim's regex options. Which is a shame because, out of the flavours covered by the book, it's the most different. The others are all more or less the same with minor quirks.
A vim reference should at least try to cover it all. That said, vim has excellent builtin help (:help regex), I was just hoping for a more complete reference on paper, in a nice little book.
On the other hand, the perl section didn't seem too bad (note that I'm the guy who contributed perlreref to 5.8.1). Points of interest: gives a nice reference to the Unicode properties (I think Perl's docs is missing a nice comprehensive list, expecting you to look elsewhere); it notes the different return values of the operators/functions in scalar vs list contexts; isn't aware of the changes in Perl to make $`, $&, and $' faster (though the outer two are only faster in a blead compiled with copy-on-write (as far as I can see); the composite unicode properties to character class equivalent mapping is somewhat more enthusiastic; the references don't mention a lot of the perl docs that I do; doesn't mention the \p{IsSpacePerl}. Other than that, quite good =)
Also, it doesn't cover Ruby regex, which have some amusing quirks of their own (in particular, the meanings applied to /s and /m, and the way Perl's /m is on by default, thus meaning ^ and $ are often the wrong thing to use).
Meanwhile, I've been collecting links and such for various regex related bits and have put a wiki page up on the topic in my kwiki.
