What are some good PHP editors?

Netbeans is a great IDE with lots of PHP support. I can't even start to name all the features I use but there are a fair amount. Check it out here:

• http://netbeans.org/features/scripting/index.html
• http://netbeans.org/features/php/index.html

I've used both Eclipse for Java and Netbeans for PHP and I feel Netbeans is a bit stronger for PHP as well as XHTML and CSS. That's my personal preference anyways.

Looking at PHPStorm I assume you're looking for something similar to it, so a full IDE. Netbeans and Eclipse are the closest to that as far as I'm familiar with.

Netbeans has most, if not all, the features that PhpStorm has on that page plus a whole lot more.

Geany

This is an advanced editor/lightweight IDE with lots of features. Like Gedit, it has syntax highlighting for PHP and is extendible through plugins. It has some more advanced features than Gedit such as code folding. It can be installed from the repositories by installing the package geany and optionally geany-plugins.

vim

Well, you have to work a little at the start to make it an IDE but it's great once you do it. It has GUI version called GVim as well. Install it with

sudo apt-get install vim-gtk

here are some tips on making it work with PHP and here are the list of plugins you can use to enhance vim to better work with php.