Piwik aims to be an open source alternative to Google Analytics.

Quickly check your site's Google PageRank, Alexa Rank and more!

Allows you to explore all the web pages indexed by Yahoo! Search. View the most popular pages from any site, dive into a comprehensive site map, and find pages that link to that site or any page.

ClickHeat is a visual heatmap of clicks on a HTML page, showing hot and cold click zones. ClickHeat is an OpenSource software, released under GPL licence, and free of charge.