The first time i knew Piwik is on sourceforge.net, because it is the “This Month’s Project” of July, 2009, and I was attracted by its brief introduce,
Piwik is a downloadable, open source (GPL licensed) web analytics software program. It provides you with detailed reports on your website visitors: the search engines and keywords they used, the language they speak, your popular pages, and a whole lot more. Piwik aims to be an open source alternative to Google Analytics.
and It cost no more 5 minutes to install on my dreamhost hosting.
It has some competitive features,
1. Piwik’s features are built inside plugins: you can add new features and remove the ones you donâ€™t need. If you are a developer, you can easily build your own web analytics plugins!
2. 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)
3. 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!
And you maybe have interesting in 7 Reasons Why Your Commercial Site NEEDS Piwikâ€¦,
#1 You Own The Data
#2 Fully Expandable Feature Set Just Like WordPress
#3 API Developer Access
#4 Real Time Tracking
#5 Total Privacy
#6 Itâ€™s Free
#7 It Will Make You More Money