I run OS X.<p>On the web development side of things, I use Django for my job and some of my more complicated personal projects and Hyde to generate a couple of smaller ones.<p>## Basic Stuff<p>- Terminal for a command line<p>- zsh and oh-my-zsh for a shell, with a whole lot of 
personal customizations (especially the prompt)<p>- Quicksilver to save my sanity<p>- homebrew to install various things<p>- pianobar and iTunes to play music (I'm also looking at dhun now though)<p>- Visor to keep pianobar out of the way but easy to reach<p>- Dropbox to sync some stuff between machines<p>- Time Machine for backing up<p>## Writing Code<p>- TextMate for editing anything but CSS<p>- CSSEdit for wrangling CSS<p>- Fluid instances for previewing<p>- Firefox to check how stuff works with Gecko<p>- Pixelmator to make/edit some very basic graphics (I'm not a designer)<p>## Handling Code<p>- Mercurial (just the CLI) with BitBucket and/or Codebasehq for version control<p>- Git and GitHub to create git mirrors of some things<p>- t and/or BitBucket/Codebasehq's issue tracker to keep track of quick tasks<p>- Transmit for the rare, rare occasion where I need to SFTP something somewhere<p>- Fabric for automating deployments and other small tasks<p>## Communicating<p>- Fever to manage my heaping pile of RSS feeds<p>- Tweetie, Adium, Mail.app to stay in touch with people<p>- Colloquy for IRC<p>- Skype for voice/video calls and screen sharing