Piwik`s features are built inside plugins: you can add new features and remove the ones you don’t need. If you are a developer, you can easily build your own web analytics plugins!
you own your data: because Piwik is installed on your server, the data is stored in your own database and you can get all the statistics using open APIs (publishing the data in many formats: xml, json, php, csv)
(NOW AVAILABLE!!!) the user interface is fully customizable: you can drag and drop the widgets you want to display and create a report especially tailored to you!

The tool tries to find counting/measurement pixel of tracking software from different services and companies.

Supported are the following:
* Cybermonitor
* eStat
* eTracker
* Google Analytics (urchin.js/ga.js)
* Infonline (IVW)
* Nedstat Sitestat
* OEWA
* Omniture Sitecatalyst
* opentracker.net
* Piwik
* Prospectfinder
* Quantcast
* Reinvigorate
* Sitemeter
* Spring
...