Braidlink is software for knot and braid theory computations. It performs both analytic and numerical manipulations of knots and braids. Cook's Borromean Ring Links Links to pages about Borromean rings and two outlines of proofs that show the Borromean rings can't be made from circular rings. The number of different Alexander, Homfly and Jones polynomials for knots of up to 15 crossings is given. The algorithm has a better time bound for large links than algorithns that ignore duplicates.
Source code is on the site.
Geometry and the Imagination Has a small section on knot theory at an introductory level. Also has sections on orbifolds, polyhedra and topology. A page of links on geometric questions arising from knot embeddings. An introduction to harmonic knots. History of Knot Theory Biographies of early knot theorists.