Uptime is a simple remote monitoring utility using Node.js and MongoDB. You can monitor thousands of websites at the same time. You can tweak frequency of monitoring on a per-check basis, up to the millisecond. You will receive instant web alerts on every page when a check goes down.

You can monitor availability, responsiveness, average response time , and total uptime/downtime. You can get details about failed checks, Group checks by tags and get reports by tag. There is complete API for integration with third-party monitoring services. And it’s easy to install with zero administration.

Requirements: -
Download Link: http://fzaninotto.github.com/uptime/
License: License Free