Epesh writes about using regular expression matching in his logging framework LN2.

I'm wondering if you've looked at JRexx:

Technically jrexx uses a minimized deterministic FSA (finite state automaton) and compiles the textual representation of the regular expression into such an automaton.

By restricting its functionality to DFA, this implementation may be extremely fast, and just the right thing for a logging tool. I'm wondering now, are there any regex benchmarking suites out there so we can compare the different regex engines available in Java?  

Regex engines written in java:

• java.util.regex
• ORO - Jakarta Perl 5 compatible regex
• Regexp - Another Jakarta project
• JRegex - Regex with named groups
• JRexx - DFA based regex
• Regex4j - uses regex syntax from XML Schema

One other interesting feature about jrexx is that they're building some kind of GUI intereface to explore the regular expression.   I think howver the "jrexx" name needs a change, Rexx is a language from IBM so I guess jrexx should mean a java implementation of Rexx, which I believe exists, its called NetRexx.