Dynamically Typed asks the question today - Which PHP libraries do you use?

For interest, wondering what PHP libraries people use? By use I mean libraries you actually trust and are willing to use / have used on a live website.

Some of the ones that he lists for himself include: phpMailer, ADOdb, PEAR::HTTP_Request, and PEAR::HTML_QuickForm.

There are tons of comments on this one, including several that support the libraries Harry already mentions...