(cat.g) is a program written by Murray Elder and Jon McCammond which tests whether or not a 3-dimensional Euclidean (simplicial) complex is non-positively curved. The program is based on an algorithm described in [1].
A significant improvement of the algorithm is described in the preprint [2]. with John Meier. The gap version has been updated to return only the output needed for the improved algorithm; the pari version has not. Thus the pari version will return more output than the gap version in response to the same questions.
At the moment the input and output of the software will seem rather cryptic. An improved interface (and some documentation) will be available soon.
software: cat.g (gap version); cat.gp (pari version)
documentation: (coming soon)