Log Analysis

Web Analytics Demystified
Includes free book chapters about web analytics, as well as a weblog about web analysis.
http://www.webanalyticsdemystified.com

Weblog Parse
Not a log analysis package by itself, rather this is a fast tool for building such packages.
http://www.acme.com/software/weblog_parse/

WiredMinds
Software and services company in the area of Web site analytic and the controlling of web-based applications.
http://www.wiredminds.com/

WUM: A Web Utilization Miner
WUM is a sequence miner. Its primary purpose is to analyze the navigational behaviour of users in a web site, but it is appropriate for sequential pattern discovery in any type of log. It discovers patterns comprised of not necessarily adjacent events and satisfying user-specific criteria.
http://hypknowsys.sourceforge.net/