Webalizer is a graphical logfile analyzer which is able to parse the following logfile formats

A typical use case of Webalizer is to execute it in a daily cron job to analyze, for example, an Apache web-server combined logfile. Webalizer will then parse the file at an astonishing pace and create detailed daily, weekly and/or monthly (depending on configuration and/or commandline options) graphs representing the various usage types. Statistics are generated as static HTML files and graphs as PNG, or Portable Network Graphics images

Recent versions of Webalizer support incremental analyzing to provide more consistent results - no matter how often webalizer analyzes a certain log before it is rotated.