Optimisation

CSScomb
CSScomb. Makes your code beautiful.
CSS Lint
Your CSS goes here. The more, the better.
JSHint
JSHint is a community-driven tool to detect errors and potential problems in JavaScript code and to enforce your team's coding conventions.
Prefix free
-prefix-free lets you use only unprefixed CSS properties everywhere. It works behind the scenes, adding the current browser's prefix to any CSS code, only when it's needed.
prefixMyCSS
Hello! prefixMyCSS is now closed. Use Pleeease Play, a much better similar tool.
WebPageTest
Run a free website speed test from multiple locations around the globe using real browsers (IE and Chrome) and at real consumer connection speeds. Y
csscss
A CSS redundancy analyzer that analyzes redundancy.
Load Images on Demand
Javascript-free solution to load images on demand as part of initial page load optimization. CSS-only brain teaser!
JS Beautifier
Beautifier for javascript at http://jsbeautifier.org/
helium-css
Helium - javascript tool to scan your site and show unused CSS.
html-inspector
HTML Inspector is a code quality tool to help you and your team write better markup.
beautify-with-words
Beautifies javascript and replaces variable names with unique "long-ish words".