Netbeans 7 is out. I've been using it for PHP, at work as well as at home, for almost two years and I have to say that it has become by far my favourite PHP IDE.
The Netbeans IDE is a project started in 1996 for Java. PHP support started since version 6.5 (late 2008). Since then, version after version, lots and lots of features have been added and they continue to grow.
All of this is opensource and it comes free of charge that means that you can download it, install it and give it a try. That's how I like it. :-)
It's Java based so it runs on any platform (Windows, Linux, Mac..).
The fact that the version 7 is out is a good moment for many PHP (and not only) programmers to try to see whether they like it or not.
Netbeans supports other languages too such as Java SE/EE and C/C++.
One nice little tip? eg, if you want to search for files press ALT+SHIFT+O.
Curios about it? Download the version you need/want from the Netbeans site.