Use The Index, Luke! : A tutorial covering SQL indexing and SQL tuning for developers: avoiding unnecessary details about database internals.
SQL indexing is the most effect...
MySQLTuner : MySQLTuner is a script written in Perl that will assist you with your MySQL configuration and make recommendations for increased performance and stabi...
webhint : webhint is a linting tool that will help you with your site's accessibility, speed, security and more, by checking your code for best practices and co...
Prepack : Prepack is a tool that optimizes JavaScript source code: Computations that can be done at compile-time instead of run-time get eliminated. Prepack rep...
Let's make the web faster : There are many ways to make websites run faster. In this section, you can discover performance best practices that real web professionals employ in th...
Minimize round-trip times : An article on the best practices to apply in order to minimize HTTP round-trip times
Mobile Perf bookmarklet : It displays a menu with links that load other bookmarklets including Firebug Lite, Page Resources, DOM Monster, SpriteMe, and CSSess. The Mobile Perf ...
localForage : localForage is a handy library that improves the offline experience of your web app by using asynchronous storage (via IndexedDB or WebSQL where avail...
Nice write-up on techniques for scaling up a web application.