Offline.js – Alert Users When No Internet Connectivity

Offline.js is a library to automatically alert your users when they’ve lost internet connectivity, like Gmail. It captures AJAX requests which were made while the connection was down, and remakes them when it’s back up, so your app reacts perfectly. It has a number of beautiful themes and requires no configuration. It has been tested on Modern browsers like Chrome, Firefox, Safari and IE8+.

Requirements: JavaScript Framework
Demo: http://github.hubspot.com/offline/docs/welcome/
License: License Free