From Open Web Analytics Wiki
This is a maintenance release that fixes a number of bugs in the 1.5.x release. Also included awesome minor feature enhancements. This is a recommended update if you are running any prior version of 1.5.x
- DoNotTrack Support - support added for the emerging DoNotTrack browser preference supposed by Firefox, latest version of Safari, and IE. OWA will now respect this browser setting if set and avoid tracking the user.
Numerous bug fixes. See OWA's Trac 1.5.3 Milestone
See the installation page for how to install OWA for the first time.
This release does not contain any database schema changes. See the updating page for more details on how to upgrade your existing OWA instance.