I voted "Others" because I prefer to use a combination of OSes, namely OS X and a Linux distro (I use Ubuntu). My desktop runs OS X and I use it mainly for my

I voted "Others" because I prefer to use a combination of OSes, namely OS X and a Linux distro (I use Ubuntu). My desktop runs OS X and I use it mainly for my visual tools. Anything having to do with image manipulation, all my browsers, and a variety of other tools run just as well, better, or exclusively on OS X. Some examples: Pixelmator, Illustrator, xScope, ImageOptim, Dash, LiveReload, MacVim etc. There's lots more software and many more reasons, but that's the gist of it. My (non-javascript) code all runs on Ubuntu, though, and I've got a Vagrant VM running any time I'm doing dev work. I used to run my dev environment in OS X but that was a huge pain in the ass because it's so extremely inefficient in so many ways. Since switching to Vagrant & VirtualBox (& Chef, but I'm looking to switch away from that) I haven't looked back, even for solo or weekend projects. I do use Windows, but only occasionally and grudgingly so I wouldn't count it in this case. I make sure the sites I build work in IE and that's pretty much it.