Note: Russ Cox is also part of the Go team at Google and was in charge of building Code Search(RIP) and when it was shut down he released the core of the indexing engine: http://code.google.com/p/codesearch/
He also wrote RE2 [1] and has published a few articles on regular expression matching [2]. I highly recommend taking some time to look through his blog, he's got some great stuff there.
Note: Russ Cox is also part of the Go team at Google and was in charge of building Code Search(RIP) and when it was shut down he released the core of the indexing engine: http://code.google.com/p/codesearch/