Koala!

Compile Less, Sass, Scss, Stylus, Jade, Coffeescript, Haml and Markdown with live browser refresh.Prepros is a web design & development tool that does all the heavy lifting needed to preprocess, optimize and test your sites and keeps your workflow supercharged.

CodeKit automatically compiles Less, Sass, Stylus, CoffeeScript, Jade & Haml files. It effortlessly combines, minifies and error-checks Javascript. It supports Compass. It even optimizes jpeg & png images, auto-reloads your browser and lets you use the same files across many projects. And that's just the first paragraph.

Scout-App is a cross-platform desktop app that delivers the power of Sass to the hands of web designers.

Say goodbye to Alt-Tab. Live.js makes sure you're always looking at the latest version of the page you're working on, whether you're writing HTML, CSS or Javascript.

A web developer tool that applies JavaScript and CSS changes without having to reload the page.

Compass is a stylesheet authoring framework that makes your stylesheets and markup easier to build and maintain. With compass, you write your stylesheets in Sass instead of plain CSS.

Write your LESS markup. Crunch it into a CSS file. Link the crunched CSS file in your HTML. CRUNCH allows you to organize your LESS/CSS styles into some well-organized libraries, and then just serve a single file to the browser. It also renders your page without relying on JavaScript or command-line geekery.

The life-saver app for web developers !Easily check syntax, minify or process all your web assets (stylesheets, scripts and templates) as you edit them with your favorite text editor!

SCSS Compiler generates formatted css styles from scss code. Beautify or minify compiled css if necessary.

SimpLESS is your easy-to-use LESS CSS compiler.

Compile less source and get CSS styles using our LESS Compiler. Beautify or minify CSS if necessary.

Compile Sass code and get CSS styles using our SASS Compiler.

Minimus is a GUI frontend for Yahoo’s YUI Compressor. Instead of using inconvenient and slow websites to compress your JavaScript and CSS, you can do it right on your Mac.