Below i list some very usefull but free open source software: Network Stuff M0n0wall – Router PFSense – Router (Based on M0n0wall) Smoothwall – Router FreeNAS – NAS Server Untangle – Webfilter CloneZilla – Hard Drive/Network Cloning Nagios – Network Monitoring WireShark – Protocal Analyzer Real VNC – Remote Support Tool FOG – Network Cloning…