I see a lot of people using EditPlus. Me, I've been using NuSphere's version of PHPEd (yeah, I bought it, but at least they send me upgrades in the mail 🙂 ).
The current version does all the handy dandy highlighting (and you can customize all the colors, even the punctuation), FTP, WebDAV (I've got mod_dav installed on my server), and CVS support (which is what I've been looking for for a while). Now I can check out the modules I'm working on and commit them without having to load up WinCVS or use TortoiseCVS (which is pretty nice).
PHPEd also comes with a full install of apache, perl, php, mysql and some webapps for windows or unix. It's a nice package, though PHPEd is a bit kludgy at times. I recommend it if you are doing PHP development full time, the project management and CVS support is nice.
On the server side, if I need to do some quick scripting, I'll just load up pico or nano and code away.
Anyone use anything really good on Unix (X Windows)?
Ed