Go to github.com/vlm/asn1c for the latest version.
Daemonlogger is a packet logger and soft tap developed by Martin Roes
Bandwidth Monitoring Tool; Console SNMP traffic monitor
Managing OpenBSD's Packet Filter with Python
Monitoring your infrastructure for free.
WAN simulator for high-latency networks
NDPMon - Neighbor Discovery Protocol Monitor
nagios-statd patch for use with python >= 2.6
yarkant.tk
Organizing the Knowledge of Humanity
Open Source System and Network Monitoring for Linux Desktop
...a work in progress.
WatchTower is a cloud server monitoring and management tool