Dabblet, created by Lea Verou, is an “interactive playground” for trying out snippets of CSS and HTML code.It uses -prefix-free, so that you won’t have to add any prefixes in your CSS code ...

A basic and properly structured HTML/CSS drop down menu can serve you just as well. In fact, it may make your site appear more responsive to not use animations and instantly display the menu instead.

A software developer from San Francisco managed to do what no one else did before, creating a fully-functional two-way chat using only CSS and HTML, completely ditching JavaScript in the process.