I don’t keep a log of websites that don’t work on FF. The last one I came across is joyn.de, a TV streaming site. They don’t tell you that it isn’t working on FF, it just crashes when trying to play a video.

For simple stuff not supporting FF is really asinine, but for deeper stuff, like hardware accellerated video streaming, it’s not quite as easy. Especially if you are, for some reason, stuck with old frameworks or in-house developed stuff.

Actually, the application that I work on (b2b software) frequently has FF-only bugs, because the frontenders in my team refuse to test every commit on FF. It’s just me finding the bugs randomly.

The thing with free and open source is that it’s not free to develop. Mozilla still needs to pay the development. Even though the source is open, 99% of the development is done by full-time (and obviously paid) Mozilla employees. Being open source doesn’t really help Mozilla bring down the development costs at all.

And that’s the second major point where Mozilla is in trouble: They don’t really have any sustainable income.