Recs.
Updated
SpecsUpdate
Pros
Pro Free, open source, and cross-platform
NetBeans is a free, GPL-licensed IDE. It can run on any computer with a Java virtual machine. If a computer has a Java virtual machine (JVM), Netbeans can run on it. Netbeans can, therefore, run on a variety of operating systems such as Windows, *nix, and Mac OS. Being open source means that developers can contribute changes to the code to have the IDE better serve them.
Pro Supports community plugins
NetBeans can be extended beyond the basic tool that you get out of the box through community made custom plugins.
Cons
Con Development has stalled dramatically
It went down from two releases a year with minor bug-fix releases to one release and no fixes. There seem to be fewer features added per release as well. There is no activity in the plugin community.
Con Multilanguaje code completion fails
I example, sometimes code completion won't help you with html marks (or scripts) inside php echo (or print) sentences, and vice-versa.
Recommendations
Comments
Flagged Pros + Cons
Pro Free and cross-platform
NetBeans is a free, GPL-licensed IDE. It can can run on any computer with a Java virtual machine. If a computer has a Java virtual machine (JVM), Netbeans can run on it. Netbeans can therefore run on a variety of operating systems such as Windows, *nix, and Mac OS.