I have been a web programmer for 5 years and I have been faithful to only 3 text editors, namely: Maguma, Dreamweaver and jEdit.
Among the 3, jEdit is my "weapon of choice". Again, this tool was introduced to me by k0n, because he's a show off. (haha! just kidding)
jEdit is written in Java and I've tried using it on Linux and Windows. It also has support for other programming & scripting language, such as java, perl, asp, php..and a lot more, you can see the list under Global options > Editing > Change settings for mode drop down box
What makes this text editor powerful is the plugins you can install to make it an advanced XML/XHTML text editor or an IDE.
Here is a screenshot of the "must have" plugins I use.
If you're using PHP, you should definitely install PHPParserPlugin and SideKick.
One of the "cool" things you can do with this editor is customizing the look&feel; if you notice I use a black background, to reduce the stress on my eyes, and I can have an upbeat Saito Hajime background image, like so:
Looks cool, eh?
So give this text editor a try, download it now!