Subversion Client:

Tortoise svn (Windows)

Ksvn (Linux)

RapidSVN (Cross Platform)

Development Environment:

Komodo Edit 4.3.x IDE (Cross Platform)

Easy Eclipse for PHP (Cross Platform)

Smultron (Editor for Mac OSX)

Local Server:

Xampp (Cross Platform)

Bitnami Wamp/Lamp/Mamp/Samp stack (Cross Platform)

PHP Version:

Latest, but it will work in PHP 4 as well. (Cross Platform)