We’ve done some design work on the Regular Expression Library, and cleaned up the code base significantly to get rid of some cruft and fix a few bugs. The site gets a surprisingly large amount of traffic, considering how esoteric a topic regular expressions are, and hopefully the new design will make it that much easier for people to search for regular expression examples. You can see some of its earlier (and much uglier) designs in the Internet Archive Wayback Machine, which has archives of the site dating back to September of 2001.
If you have suggestions for RegExLib.com, please let us know. One thing I think I want to start doing more of is adding additional reference material to the site, such as articles, tutorials, and walkthroughs. Another feature that should come in the next update (probably 3-6 months from now) will be tagging support for the expressions, which should make it much easier to locate the expression you need.