uptimerobot

Monitor Scout is a leading website and server monitoring company, with a wide selection of flexible, high quality services. The reliable web-based system monitors your websites and server 24/7 and …

Versionista was designed for the rough-and-tumble world of today's Web, where subtle edits can offer actionable tactical advantage. * Monitor entire Web sites and receive e-mail alerts when changes...

Website monitoring (HTTP HEAD/GET), service monitoring (TCP socket test), e-mail and URL alerts. Open source at https://github.com/TomHetmer/Runtime

Automatically check your website's uptime, performance & quality with Simonbot. Be the first to know if something is going wrong with your website, get results, analyse them and find bottlenecks. …

Webmon is a Realtime Website Monitoring and Escalation Service. Webmon is a website availability monitoring and escalation service that allows you to monitor your online services and get notified upon...

WebSitePulse is a leading provider of advanced, independent and remote monitoring services that enable clients to increase the efficiency of their mission-critical e-business operations, and to reduce their...

Snapmon lets you monitor your servers to make sure everything is running. When a server goes down, you can be notified by SMS Text Message, Email, AIM, or Google Talk.

1 minute availability monitoring service for only $4.92/month. Monitoring stations on 4 continents, email, SMS and RSS alerts.

Monitorius is simple uptime monitoring service for all your needs - website monitoring, server monitoring, ping monitoring made really easy.