Abrowser (installed by default) and IceCat (proposed by default the first
time you run Abrowser) are. Both are based on Firefox. And there are other
free Web browsers: check out the "World Wide Web" and "World Wide Web
(universe)" categories in the "Synaptic package manager".
Firefox basically is free software in the sense that all its code is
available under the term of a free license. However, it raises more subtle
(yet important) problems:
Firefox implements the Encrypted Media Extensions (for DRM);
It recommends nonfree add-ons and plug-ins;
Its trademark is problematic (if I remember well, you are not allowed to sell
Firefox without first changing its name/logo).
