Abrowser is Trisquel's version of Mozilla's popular web browser with the trademarked logos replaced. Replacing the trademarked logos gets rid of the trademark restriction that forbids selling the software, which would have effectively made it non-free software.
The Trisquel project maintains a list of free software add-ons for Abrowser. It is not currently possible to install add-ons directly from within Abrowser so if you wish to install an add-on you must do so from this site.
Midori is the default web browser for Trisquel-mini. It is simple and fast using webkit technology.
Abrowser, IceCat and Trisquel
Ruben, the main developer of Trisquel has commented on the reasoning of maintaining two separate, yet very similar, browsers in the following Reddit thread. To sum up from Ruben's writing:"
Abrowser, other that saner default settings to improve privacy, is pretty much Firefox and should provide a quite "neutral" browsing experience. IceCat on the other hand includes more aggressive freedom and privacy features".