regina-gui — Regina's graphical user interface


regina-gui [file...]


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, it offers a range of combinatorial and algebraic tools, plus support for normal hypersurfaces. Regina comes with a full graphical user interface, as well as Python bindings and a low-level C++ programming interface.

This starts the full graphical user interface, and is the usual way of starting Regina. Any files passed on the command-line will be opened on startup.

MacOS Users

If you downloaded a drag-and-drop app bundle, this is the program that runs when you open it. The executable itself is simply called Regina, not regina-gui.

See Also


Regina comes with a rich users' handbook, which you can access via HelpRegina Handbook in the menu. You can also read the users' handbook online at


Many people have been involved in the development of Regina; see the acknowledgements page for a full list of credits.