GoAccess is a real-time web log analyzer and interactive viewer
Intelligently block brute-force attacks by aggregating system logs
AWStats Log Analyzer
ISC dhcpd leases usage analysis
Snare Enterprise: bit.ly/Snare-Trial
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
Free-SA is report generating tool for web, proxy and mail log files
Squid log data warehouse
Log text into graph on python and javascript.
Piwik - Remixed!
Full Featured Windows Command Line Syslog Logger