Tim Bray compares Perl and Java regular expression performance with the result of Java performing twice as fast as Perl when output performance is factored out.  Fantastic.  I knew Java regular expression library was fast but I didn't know it was this fast.  Even more encouraging, there are even faster third party regular expression libraries for Java.  I wonder if .NET 2.0 makes up for the lackluster RegEx performance in .NET 1.1.

Update:

Jeff Atwood is getting completely different result (.NET RE faster by ~40%) from an informal benchmark I did a while back (.NET slower by ~60%).  BTW, I don't believe .NET RE is 20 times slower than Java RE.