A network security analysis and monitoring toolkit Linux distribution.
Anti Spam SMTP Gateway
Free UTM appliance: firewall, VPN, WAF and antivirus in one ISO.
Command line tool for managing Amazon S3 and CloudFront services
The box to keep the Internet under your control
Xplico is a Network Forensic Analysis Tool (NFAT)
PotHead
Open Source SIEM
Scalable, distributed monitoring system for high-performance computing
a secure, open source OS for use inside USEagency facilities
Collects data about network useage using libpcap.
Batch system monitoring and archiving
Monitoring your infrastructure for free.
WatchTower is a cloud server monitoring and management tool
something that writes code for you