Cumulus Linux - Build an efficient, affordable data center network using open networking software that runs on Linux using web-scale principles.
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.
CloudView NMS - CloudView is a standards-based network management and monitoring system (NMS).
Pandora FMS - Pandora FMS: Opensource monitoring software
cStatus - Monitor and scan a network.
Zabbix - Track, record, alert and visualize performance and availability of IT resources