GoAccess is an open source real-time Apache log analyzer and interactive viewer that runs in a terminal in *nix systems. It provides fast and valuable HTTP statistics for system administrators that require a visual server report on the fly.
All credits go to http://www.ubuntugeek.com/goaccess-visual-apachenginx-log-analyzer.html
Essentially, the way GoAccess works is that it will parse the well-known Apache access log file, from there, GoAccess will collect data from the parsed log and it will display it to the console or the X terminal. The collected information or generated reports will be displayed to the user/sysadmin in a visual/interactive window. Reports include:
General Statistics, bandwidth etc.
Requested static files, images, swf, js, etc.
404 or Not Found
Browsers and Spiders
Hosts, Reverse DNS, IP Location
HTTP Status Codes
Different Color Schemes
Unlimited log file size