WebMatrix Supports CoffeeScript
Microsoft WebMatrix has numerous new features in version 2, including: code completion for PHP, C#, Razor; iPhone and iPad emulators for mobile web development; Less, Sass, Scss, and CoffeeScript support; Nuget Gallery support that even allows me to download Orchard Modules and Themes; node.js support; etc. I mainly use Sublime Text 2 and JetBrains WebStorm / RubyMine for casual website development, but WebMatrix is free and now feature-rich providing a nice alternative.
