Apache HTTP Server - Apache httpd has been the most popular web server on the Internet since April 1996
Pingdom - With website monitoring from Pingdom you will be the first to know when your website is down. No installation required. 30-day free trial.
Microsoft IIS - Internet Information Services is a web server for Microsoft Windows
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Apache Tomcat - An open source software implementation of the Java Servlet and JavaServer Pages technologies
Better Uptime - We call you when your website goes down