@phpdeveloper.org
Justin Silverton has compiled a large list of PHP editors that are offered on the web today. It's by no means a comprehensive list (I'm sure additions would be welcome), but it does give a good overview of what they are (basic stats) and a personal rating they've given it.
Among those on the list, included are:
Each of the editors on the list is linked to the php-editors.com review for it, giving you more information than just the version, license, OS, and general rating in Justin's post.