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.
Nagios - Complete monitoring and alerting for servers, switches, applications, and services
Lansweeper - Lansweeper discovers Windows, Linux and Mac machines in your network.
Gitwin - Enable your Windows system as a powerful and secure Git repository. Supports ssh, http(s) transports. Gitweb with highlighter and gravatar support available.
Zabbix - Track, record, alert and visualize performance and availability of IT resources
LANState - LANState - Network Mapper and Device Monitor