I apologize of already asked by someone else, but what (in your opinion) is the best package for computing HOMFLY polynomials?
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$\begingroup$ What do you mean by "best"? Is there something particular you'd like to accomplish? $\endgroup$ – Ryan Budney Feb 19 '13 at 22:59

$\begingroup$ @Ryan: I want to compute the HOMFLY polynomial of (3,19) cable over trefoil. $\endgroup$ – minimax Feb 20 '13 at 0:03

1$\begingroup$ The KnotTheory` Mathematica package, available with lots of documentation and examples at katlas.org/wiki/Setup, can compute HOMFLY and many other knot polynomials and even produce cables for you automatically. $\endgroup$ – Steven Sivek Feb 20 '13 at 0:21

$\begingroup$ @Steven: Thanks, I will try it out! $\endgroup$ – minimax Feb 20 '13 at 1:11

1$\begingroup$ There's also burtleburtle.net/bob/knot/homfly.html $\endgroup$ – Loop Space Feb 20 '13 at 9:48