Setup a complete PHP development environment in Windows
Eclipse is a fantastic IDE for PHP development. The best part is that it is free! It is a Java development environment that can be extended to edit Ruby, Perl, Python, PHP, C++ and many other obscure languages.
I went through a number of hurdles to get my development environment setup, but I came across this posting the other day that highlights all the necessary steps. The article covers SVN, Eclipse, PHP and Mysql installation.