That's a great question. As you may know, Mozilla doesn't build Firefox for Solaris, it is a community project. For the most part, support volunteers like me are not familiar with the procedures for contributed builds. Finding a contributed build on Mozilla's servers is somewhat hit or miss. For example, this was the most recent that I saw, for Open Solaris and Solaris 10 (which may or may not work on Solaris 11, I have no idea): http://releases.mozilla.org/pub/firefox/releases/38.2.1esr/contrib/ This page shows the same version: https://unixpackages.com/packages/mozilla To find out what other Solaris 11 users are doing, you could post here: * https://community.oracle.com/community/server_%26_storage_systems/solaris/solaris_11