#1: SpinKit
An assortment of loading indicators animated with the style sheet language CSS. Created by Tobias Ahlin, SpinKit uses CSS animations to design smooth and simple customizable animations.  

#2: jQuery.adaptive-backgrounds.js
This jQuery plugin, created by Brian Gonzalez, extracts the dominant color of an image and applies it to the background of its parent element. There’s also an option to include a cross-origin attribute in your image, and if you use it, Gonzalez congratulates you on being a “super-developer”!

#3: Myth
“CSS the way it was imagined.” This CSS preprocessor, created by Segment.io, allows users to write pure CSS without worrying about slow browser support. It still gives users the benefit of tools like Sass and LESS, and users can still use variable and math functions. Myth also allows users to reprocess anyone’s CSS without having to rewrite the code in a different syntax.

#4: Vim.js
This JavaScript port of Vim, created by Lu Wang, is a tool/toy for non-beginners. It includes the most common features of Vim.

#5: Knwl.js
This natural processor in JavaScript, created by LoadFive, scans through text, user data or just about anything for data of interest, including locations, e-mails, times, dates, phone numbers and more. Users can even check if text contains spam, and get the estimated reading time of the string.