The Dude - MikroTik is a Latvian company which was founded in 1996 to develop routers and wireless ISP systems. MikroTik now provides hardware and software for Internet connectivity in most of the countries around the world.
runit - runit is a cross-platform Unix init scheme with service supervision, a replacement for sysvinit...
Pandora FMS - Pandora FMS: Opensource monitoring software
sysvinit - Savannah is a central point for development, distribution and maintenance of free software, both GNU and non-GNU.
cStatus - Monitor and scan a network.
M/Monit - Monit is a free open source utility for managing and monitoring, processes, files, directories and filesystems on a UNIX system. Monit conducts automatic maintenance and repair and can execute meaningful causal actions in error situations.