Programming Language
PHP 5 only.
Don't hold your breath, but I'd like to learn Python.
Text Editor
Desktop: TextMate
Terminal: Emacs with PHP code syntax highlighting
Stack
MAMP (Mac, Apache, MySQL, PHP) with PHP 5 enabled. Only coding in PHP 5
Version Control
private SVN at Unfuddle
public Git at http://github.com/sillygwailo