Gfan is a software package for computing Groebner fans and tropical
varieties. These are polyhedral fans associated to polynomial ideals.
The maximal cones of a Groebner fan are in bijection with the marked
reduced Groebner bases of its defining ideal. The software computes
all marked reduced Groebner bases of an ideal. Their union is a
universal Greobner basis. The tropical variety of a polynomial ideal
is a certain subcomplex of the Groebner fan. Gfan contains algorithms
for computing this complex for general ideals and specialized
algorithms for tropical curves, tropical hypersurfaces and tropical
varieties of prime ideals.  In addition to the above core functions
the package contains many tools which are useful in the study of
Groebner bases, initial ideals and tropical geometry.

This port provides gfan together with some handy symlinks. The static
library libgfan.a is provided by the port math/gfanlib.

WWW: http://home.math.au.dk/jensen/software/gfan/gfan.html