AWStats is a short for Advanced Web Statistics. It's a free tool that
generates advanced web server access statistics graphically.

This web server log analyzer works as a CGI or from command line and
shows you all possible information your log contains, in few graphical
web pages. It uses a partial information file to be able to process
large log files, often and quickly.

It can analyze log files from IIS (W3C log format), Apache log files
(NCSA combined/XLF/ELF log format or common/CLF log format), WebStar
and some other web, proxy or WAP servers (and even some FTP servers).