50 Javascript libraries for charts and graphs

Link here.

Want to tell your users to update their browser version?

Link here.

Awesome text animations

Link here.

Looking to make a jquery plugin?

Lots of jquery plugin patterns to start off here.

A small fun experiment on audio input.

Link here.
(Works only in chrome as of now).

Want to check if gzip compression is working on all files you want on your website?

Link here.

Readymade plugin for Paypal 'Buy now!'

Link here.

Match your selectors using substrings in CSS3

Link here.

One stop for all nodejs needs

Link here.

Create your own analytics dashboard

Link here.

Cool patterns and background through just css

Link here.

Super cool windows UI type animation

Link here.

Create tooltip type of toolbars!

Link here.

Tutorial to create an animation on canvas using image sprites.

Link here.

Awesome and free Slideshow plugin!

Link here.
It's responsive too! 

Get a hold on File API

Link here.

Create your own custom font icons using command line from svg images

Link here.

Watch the changes in any object or attribute

Link here.

Content security policy explained

HTML5 Rocks has a complete article on content security policy to save us from cross site scripting!

Check broken links on your website

Link here.