The Free & Popular opendhcp application for Physical & Virtual Machine
TraceMAC is a command-line Layer 2 traceroute for Cisco switches
Anti Spam SMTP Gateway
ipset set listing wrapper script
A simple, handy network addressing multitool with plenty of features.
Energy and environmental monitoring of the server room
Programmable completion code (bash) for ipset (netfilter.org)
High interaction honeypot solution for Linux based systems
MitM pentesting opensource toolkit
[UPDATE 28-10-2015] FINAL MULTIPLINK SSH LIFETIME v2.0 UP-5 "FAREWELL"
Easy to use firewall for linux beginners.