A declarative, efficient, and flexible JavaScript validation library for Humans. V4f provides a lot of rules that you can use to build complex validation without the need to be a javascript expert.

Simple tooltips made of pure CSS and made by Claudio Holanda. Balloon.css lets you add tooltips to elements without JavaScript and in just a few lines of CSS.

Learn how to compare two dates in JavaScript with various methods by Saruque Ahamed Mollick.