Webalizer

The Webalizer is a fast, free web server log file analysis program. It produces highly detailed, easily configurable usage reports in HTML format, for viewing with a standard web browser.
Features:

• Is written in C to be extremely fast and highly portable. On my 1.6Ghz laptop, it can process close to 70,000 records per second, which means a log file with roughly 2 million hits can be analyzed in about 30 seconds.
• Handles standard Common logfile format (CLF) server logs, several variations of the NCSA Combined logfile format, wu-ftpd/proftpd xferlog (FTP) format logs, Squid proxy server native format, and W3C Extended log formats. In addition, gzip (.gz) and bzip2 (.bz2) compressed logs may be used directly without the need for uncompressing.
• Generated reports can be configured from the command line, or more commonly, by the use of one or more configuration files. Detailed information on configuration options can be found in the README file, supplied with all distributions.
• Supports multiple languages. Currently, Albanian, Arabic, Catalan, Chinese (traditional and simplified), Croatian, Czech, Danish, Dutch, English, Estonian, Finnish, French, Galician, German, Greek, Hungarian, Icelandic, Indonesian, Italian, Japanese, Korean, Latvian, Lithuanian, Malay, Norwegian, Polish, Portuguese (Portugal and Brazil), Romanian, Russian, Serbian, Slovak, Slovene, Spanish, Swedish, Thai, Turkish and Ukrainian are available.
• Unlimited log file sizes and partial logs are supported, allowing logs to be rotated as often as needed, and eliminating the need to keep huge monthly files on the system.
• Fully supports IPv4 and IPv6 addresses. Includes built-in distributed DNS lookup capability and native Geolocation services.
• Distributed under the GNU General Public License, complete source code is available, as well as binary distributions for some of the more popular platforms. Please read the Copyright notices for additional information.