documentation for Regina, the topology software

 Regina is a software package for low-dimensional topologists. This package
 provides a rich users' handbook, complete API documentation for the C++
 calculation engine and Python bindings, and the full specification for
 Regina's XML data file format.
 .
 Regina focuses on the study of 3-manifold and 4-manifold triangulations,
 knots and links, normal surfaces, and angle structures. For Regina's
 standard graphical user interface, and for more information about what
 Regina can do, see the package regina-normal.