I don't know anything about FeynCalc in particular, but I do have one
comment on the copyright issues. CY says:
> FeynCalc is ... LGPL according to the lastest readme, which
> isn't terribly relevant since we can't use it directly but
> does indicate that a direct translation is not likely to
> raise objections.
Actually, the fact that it is LGPL *is* relevant. It means that a
translation of it from Mathematica code into Maxima code is explicitly
permitted by its license, and that the resulting translation (a "derived
work" under copyright law) is also subject to the LGPL.
That said, if FeynCalc (or any other package) were translated one-shot
into Maxima code, the original and translated versions would not benefit
from development work on the other version, which would not be a good
thing....
-s