Servers Alive!

An uncompromising mature enterprise-level platform designed for real-time monitoring of millions of metrics collected from tens of thousands of servers, virtual machines and network devices, effortlessly scaling to even larger environments.

Join millions of IT professionals and download Spiceworks, a free network monitoring software with network management tools, help desk ticketing app, network mapper and more.

Pingdom web site monitoring and other infrastructure for you and instantly let you know when anything goes wrong. Measure uptime, downtime, and the performance of your website as experienced by visitors.

OpenNMS is an enterprise grade network monitoring and network management platform developed under the free software or open source model. It consists of a community-supported, free-software project as well as an organization offering commercial services, training and support.

NodePing Server Monitoring and Web Site Monitoring. Simple but powerful Internet service monitoring. Checks as frequent as once a minute.

Port Monitor is an easy and online tool that does website and server monitoring for you 24/7 every 60 seconds and sends you or your co-workers instant email/push notifications when something goes wrong.

Monitis is a Cloud monitoring and IT analytics service offering Website Monitoring, Server Monitoring, Network Monitoring, Application Monitoring, Cloud Monitoring, and Custom Monitoring.

PushMon is a new kind of cloud-based monitoring system. Instead of checking public facing servers on a regular basis, PushMon will wait for pings from the objects being monitored. These objects are usually batch jobs, scheduled/cron scripts, backups, or test scripts, but really are anything that has access to the internet and can call a URL on a regular basis. If PushMon does not receive the URL "ping" by the specified schedule (like every hour, or every day or even by 5:00 PM every Fri), it will send an alert (email, IM, SMS, Twitter and/or phone call). We can monitor your database backups, your cron scripts, your background tests, your internet connectivity, your batch jobs, and a lot more. We also have an advanced but easy to use scheduling feature to alert you of problems as soon as possible. »

RapidSpike is an uptime and performance monitoring service for websites and web applications. It simplifies monitoring, alerting and reporting to support your online presence and to ensure a positive user experience. Organisations use it to identify problems, measure performance and improve capacity planning.

Website monitoring service that offers a comprehensive free plan with:* escalation levels (if a first-responder contact doesn't acknowledge the downtime, another contact will be alerted)* search for text on the website to detect defacing/hacking in addition to downtime

The website monitoring service that doesn't suck. Get an email when your website goes down. Statuses are available by email, web, RSS feeds and widgets.

With webcron you pay per request and you can choose the monitoring frequency to your linking. When your website goes down, webcron can send you either an email or a text message (SMS).