OPTi
- http://vivaldi.ics.nara-wu.ac.jp/~wada/OPTi/
- Macintosh freeware which visualizes quasi-conformal deformations of the once-punctured-torus groups. It interactively draws the isometric circles, the Ford region, and the limit set.
SNAP
- http://www.ms.unimelb.edu.au/~snap
- Exact computation of hyperbolic 3-manifolds and their arithmetic invariants. Written by O. Goodman in an ARC-funded project of Hodgson and Neumann.