# regina-gui

## Name

regina-gui — Regina's graphical user interface

## Synopsis

regina-gui [`file`...]

## Description

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-python.

Regina comes with a rich users' handbook, which you can access via Help→Regina Handbook in the menu. You can also read the users' handbook online at regina-normal.github.io.

## Author

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