This app is for research mathematicians in 3-manifold and 4-manifold topology.

Have you encountered 3-manifolds and normal surfaces, or heard about the desktop software packages Regina or SnapPy? If so, then you might find this app useful. If not, but if you are curious as to what it's all about, you might like to read about the Poincaré conjecture (é-conjecture), or hunt down a copy of Jeffrey Weeks' excellent book "The Shape of Space".

Regina is a software package for 3-manifold and 4-manifold topologists, with a focus on triangulations, normal surfaces, and angle structures. For 3-manifolds, it includes high-level tasks such as 3-sphere recognition, connected sum decomposition and Hakenness testing, comes with a rich database of census manifolds, and incorporates the SnapPea kernel for working with hyperbolic manifolds. For 4-manifolds, Regina offers several combinatorial and algebraic tools, as well as support for normal hypersurfaces. Advanced users can also access Regina's mathematical engine using Python scripting.

This Mac App Store version is almost identical to the Mac app that you can download from the Regina website. The main difference is that it is sandboxed, which is excellent for security but which limits your ability to read and write arbitrary files from Python.

If you have any questions, requests or feedback then please contact Ben or the Regina development team – see for details.

What’s New

Version 5.1

This release is a major overhaul for Python users:

– All of the code that was deprecated in version 5.0 has now been removed entirely. See for instructions on how to update your scripts.

– Many class names have changed, but most of these changes follow a standard pattern (classes of the form NFoo become Foo). The old class names have been kept, and will not be removed until Regina 6.0. See for details.

– More of Regina's triangulation code is now generic, which means you can do more with higher-dimensional triangulations (e.g., triangulate boundary components, or compute homology).

This release also includes minor enhancements to the mathematics and the user interface (e.g., a Windows menu, better syntax highlighting for script packets, and the ability to cancel long Turaev-Viro calculations).


Benjamin Burton
49.2 MB

OS X 10.6.6 or later, 64-bit processor



Age Rating
Rated 4+
© 1999-2016 The Regina development team


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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