Geomview and OOGL are part of an ongoing effort at the Geometry Center to provide interactive 3D graphics software which is particularly appropriate for displaying the kinds of objects and doing the kinds of operations of interest in mathematics research and education. You can compute an OOGL data file of a mathematical object that would be difficult or impossible to build a model of in the real world. In geomview, besides examining an object in ordinary Euclidean 3-space, you can look at objects in hyperbolic 3-space and Euclidean 4-space. The hyperbolic model is the projective one, where geodesics are straight lines and isometries are represented as 4x4 projective matrices. While geomview is tailored for mathematical visualization, it is written to be extensible and can serve as a general-purpose tool. Its functionality can be extended in an almost unlimited fashion by external modules. WWW: http://www.geomview.org/