GoAccess is a real-time web log analyzer and interactive viewer
Fast and Lightweight Logs and Metrics processor for Linux, BSD, OSX
AWStats Log Analyzer
Intelligently block brute-force attacks by aggregating system logs
ISC dhcpd leases usage analysis
Snare Enterprise: bit.ly/Snare-Trial
Kafka implemented in Golang with built-in coordination
Open Source SIEM
A multi-platform universal log collector and forwarder
Log File Monitoring - Check Log Files, Analyze, Alert on any UNIX Log
Free Syslog Server for Windows with a graphical user interface
Visual Syslog Server for Windows with a graphical user interface.
Free-SA is report generating tool for web, proxy and mail log files
Squid log data warehouse