Ah, the long and colourful history of Fizzilla . . .
Short version of the story is yes and no. To everything. There are two ways to port Mozilla to OS X, FizzillaMach and FizzillaCFM (the latter being the CodeWarrior necessitating version).
FizzillaMach is the variant compiled via cc. To the best of my knowledge, it has been compiled, but no one has yet been able to get it to run. On the other hand, I know that Mike Pinkerton is working on getting a FizzillaMach (Carbon) port of 0.9 done sometime in the near future, as time permits.
Info on configureing the build environment is at
http://www.mozilla.org/ports/fizzilla under the FizzillaMach section. Its probably best to grab the patches which have yet to be checked in from the Fizzilla BugZilla entry.
Hope that was of some help.
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ChangeIsTheOnlyConstant