// Workers AI · dad joke modeWhat did Regina the program say? "I reign supreme.

Regina
Original authors	Ben Burton, David Letscher, Richard Rannard, Hyam Rubinstein
Developers	Ben Burton, Ryan Budney, William Pettersson
Release	December 2000
Stable release	7.3 / March, 2023
Written in	C++, Python
Operating system	Linux, Unix-like, Mac, Microsoft Windows, iOS
Available in	English
Type	Mathematical Software
License	GPL
Website	regina-normal.github.io
Repository	github.com/regina-normal/regina

Regina is a suite of mathematical software for 3-manifold topologists. It focuses upon the study of 3-manifold triangulations and includes support for normal surfaces and angle structures.

Features

• Regina implements a variant of Rubinstein's 3-sphere recognition algorithm. This is an algorithm that determines whether or not a triangulated 3-manifold is homeomorphic to the 3-sphere.
• Regina further implements the connect-sum decomposition. This will decompose a triangulated 3-manifold into a connect-sum of triangulated prime 3-manifolds.
• Homology and Poincaré duality for 3-manifolds, including the torsion linking form.
• Includes portions of the SnapPea kernel for some geometric calculations.
• Has both a GUI and Python interface.

See also

• Computational topology