Nagios
Open Source
Nagios known as Nagios Core, is a free and open source computer-software application that monitors systems, networks and infrastructure.
PHP Server Monitor
Open Source
PHP Server Monitor is an open source tool to monitor your servers and websites.
HappyApps
Freemium
HappyApps is an online app uptime monitoring platform.
Compare Port Monitor with alternatives
Compare Nagios and Port Monitor and decide which is most suitable for you.
Compare HappyApps and Port Monitor and decide which is most suitable for you.
Compare PHP Server Monitor and Port Monitor and decide which is most suitable for you.