Topology Software

Complete applications

• SnapPy: A user interface to the SnapPea kernel which runs on Mac OS X, Linux, and Windows. SnapPy combines a link editor and 3D-graphics for Dirichlet domains and cusp neighborhoods with a powerful command-line interface based on the Python programming language. Download/Install and Full documentation.
  Version 1.6 new in August 2012!
• PLink: A graphical editor for piecewise linear link projections, which can export DT codes and SnapPea link files. Download/Install and Full documentation. Version 1.1 from June 2009.
• Gridlink: is a graphical tool for manipulating link projections consisting of vertical and horizontal arcs in the plane. These projections are used in Ivan Dynnikov's recognition algorithms for split links and the unknot. They also are used in the combinatorial description of knot and link Floer homology given first by C. Manolescu, P. Ozsvath and S. Sarkar, and explained further by C. Manolescu, P. Ozsvath, Z. Szabo and D. Thurston. The program can accept a closed braid description of a link, and can automatically simplify the projection. It also computes mod 2 Heegaard Floer Knot homology, using the py_hfk module described below. Packages and installation instructions for UNIX, OS X, and Windows are on the gridlink home page.
  Last update: 28-Mar-2007
• Heegaard: John Berge's famous program is now available here. The program can construct a Heegaard diagram from a group presentation, if the presentation is realizable, and use geometric T-transformations to simplify the diagram. A 1998 Mac OS9 binary is available. (Unpack with Stuffit Expander.) The program has also been ported to gcc. The gcc port is available in source form, either as a tarball or as individual files . Check the README file for instructions on compiling and using the program. The source distribution also contains extensive documentation describing the theory behind how the program works: there is a 30 page article available as PDF or TeX. There is also a set of examples in UNIX or MAC OS 9 format. The MAC OS 9 version of the program has a graphics module for drawing Heegaard diagrams. Unfortunately, the graphics is not yet available in the gcc port.
  Last update: 23-Dec-2010

Python libraries

• t3m: A box of tinker toys for topologists. Use it for studying triangulations of 3-manifolds at the Python prompt. It is written entirely in Python, so you can take it apart and put it back together your own way. Requires Python-2.2. T3m is available as a tarball, or as individual files.
  Last update: 12-July-2010
• CyPari: A stand-alone version of Sage's Python interface to the PARI number theory library. CyPari is available as a tarball, as individual files, or via as prebuilt binary eggs which you can install via

  python -m easy_install -f http://snappy.computop.org/get CyPari

  Last update: 31-July-2012
• Spherogram: A Python module for dealing with the kind of planar diagrams that arise in 3-dimensional topology, such as link and Heegaard diagrams. Spherogram is available as a tarball, as individual files, or via as prebuilt binary eggs which you can install via

  python -m easy_install -f http://snappy.computop.org/get spherogram

  Last update: 31-July-2012
• FXrays: A small, fast C implementation of an algorithm for finding extremal rays of polyhedral cones with filtering. It is intended to be used to find embedded normal surfaces in triangulated 3-manifolds. You can build it either as a C module for linking with your own code, or as a Python module. FXrays is available as a tarball, or as individual files.
  Last update: 06-Aug-2003
• py_hfk: A Python binding for the C++ code written by John A. Baldwin and W. D. Gillam to compute mod 2 Heegaard Floer Knot homology. Some modifications have been made to increase speed and reduce memory usage. The original code is available here. The python package is available as a tarball, or as individual files.
  Last update: 27-Jan-2007

C libraries

• SnapPeaKernel. As of September 2009, t3m is the proud host of the official repository for Jeff Weeks' SnapPea library, on which SnapPy and many other programs are based. Source code: as a tarball or as individual files. You can also access the Mercurial repository directory via "hg clone http://math.uic.edu/t3m/hg/SnapPeaKernel".
  Last update: 9-Sept-2009

Deprecated software

• Our extended version of Jeff Week's SnapPeaPython is available as a tarball, or as individual files. Requires Python-2.2. Superseded by SnapPy above.
  Last update: 25-Jul-2008

The development of this software was partially supported by the National Science Foundation under grants numbers 0204142, 007160, 0405491 and 0707136.