LiveReload - LiveReload 2 proudly presents… The Web Developer Wonderland. (a happy land where browsers don't need a Refresh button). CSS edits and image changes apply live. CoffeeScript, SASS, LESS and others just work.
Browsersync - Browsersync makes your tweaking and testing faster by synchronising file changes and interactions...
CodeKit - CodeKit allows you to optimize the performance of your website by automatically and efficiently compiling a variety of popular languages.
Ghostlab - Ghostlab allows you to test out a newly developed website on a variety of browsers and mobile devices at the same time. To get started, simply drag the web address to the Ghostlab system and press the play button. Read more about Ghostlab.
Prepros - Compile Less, Sass, Scss, Stylus, Jade, Coffeescript, Haml and Markdown with live browser refresh.
Vim Awesome - Awesome Vim plugins from across the universe