Xplico is a Network Forensic Analysis Tool (NFAT)
Count the number of people around you by monitoring wifi signals
DSL for writing communication benchmarks
Live DVD with CORE network simulator
Middleware for distributed applications
PotHead
Open Source SIEM
Energy and environmental monitoring of the server room
Scalable, distributed monitoring system for high-performance computing
[UPDATE 28-10-2015] FINAL MULTIPLINK SSH LIFETIME v2.0 UP-5 "FAREWELL"
fully modular opensource firmware for the ez430 chronos
a secure, open source OS for use inside USEagency facilities
Hierarchical Cluster Engine project
Collects data about network useage using libpcap.
NetStress is a DDoS and network stress testing tool.
ss7mon an SS7/SIGTRAN signalling monitor
Managing OpenBSD's Packet Filter with Python
Tool for identifying Network Service Dependencies