There are already loads of resources on the interwebs explaining the purpose of regular expressions so no need to explain further here. (Well basically, they allow you to match and extract patterns of text from strings). I just want to document a few quick examples that I use a lot.

Every one knows IE6 sucks and deserves to die in the firey pits of hell. IE7 was a bit better, and after lots of hair pulling and css hacking we were able to get our websites to look pretty much the same across all the major browsers. So when IE8 came out our sites were sure to keep working. Right?...

Building html emails is a royal pain in the arse. Every email clients buggers up something along the way. Here’s the most annoying things I’ve figured out along the way…

Integrating forums with your own application and user base can be a real pain in the ass. I’ve done this in the past with Vbulletin and phpBB, but it’s really not that much fun. Both involved some degree of hacking of their core code which means problems when trying to upgrade (you have to remember every tiny thing you did to make it work). As both products improve and get more advanced you’d think they’d have built nice apis to make this job easier. Apparently not yet…