Open Web Analytics is an open source framework that developers can use to integrate web analytics into any application.

It is built with PHP & besides the standalone usage, it has built-in support for WordPress, Gallery & MediaWiki.

OWA comes with 2 APIs:

• PHP: which makes it easier to integrate into any PHP application
• JavaScript: for usage in non PHP pages/websites

It has powerful tracking/reporting features like heat maps, multiple websites, Google Maps integration, RSS/Atom subscription tracking &standard ones like:

• page views, visits, and unique visitors over time
• unique, new, repeat visitors over time
  
• Click-streams – view the actual click-stream of each visitor
• Click Tracking – Track where exactly on a web page users are clicking and view clicks by browser type
• Click Heat Maps – view a heat map of where users are clicking on your web pages
  
• Visitor Aging – understand the age of your repeat visitors.
• Canned and Custom Time Periods – generate reports using pre-defined reporting periods or custom date ranges
• Refering Page Analysis – View the title, anchor text, and surrounding text of inbound links from refering web pages
• View visits by user agent
• Track entry and exit pages
• Track pages by custom page type

The frameworks uses other open source resources like Open Flash Chart or PHP Mailer & requires PHP 4.2.2+ with GD enabled to run. 

Requirements: PHP 4.2.2+ With GD Enabled, *nix Servers
Compatibility: All Major Browsers