LogSniffer
LogSniffer is a perl-script used to analyse Web Server Logs. It has as many features as many commercial programs currently available. Some of its features are: Internal Support for Common Logfile Format, Referrer Log, User Agent Log, Extended Logfile Format, Apache Cookie Log, Via the custom logtype you can teach LogSniffer how to analyse almost any logtype that exists, and HTML Stats output including total summary, daily stats, file stats, referrer stats, user stats, auth stats, and more,