Vex – Modern & Lightweight Modal Boxes

Vex is a JavaScript library for creating very good looking modal boxes.

The library is standalone + lightweight (2kb minifed + gzipped) and comes with an easy-to-use API.

JavaScript Dialogs - Vex

It has smooth animations, a built-in CSS spinner and replaces alertconfirm, and prompt out of the box.

Vex also works well on mobile browsers and its design can be customized quickly.