Log Validator is a web server log analysis tool with focus on the quality
of Web documents. Thanks to a modular, extensible design, the Log Validator
can help Web authors find the most popular content on their web site that
matches a particular criteria.

The Log Validator was first written with Validation (HTML, etc.) in mind :
it can thus help web content managers find and fix the most frequently
accessed invalid documents on their Web site, acting as a comprehensive,
step-by-step validation tool.

WWW: http://www.w3.org/QA/Tools/LogValidator/