CDEG: Computerized Diagrammatic Euclidean Geometry

This is the home page for CDEG: Computerized Diagrammatic Euclidean Geometry, which impliments a formal system for giving diagrammatic proofs in planar geometry that are similar to the kinds of proofs Euclid gives in the Elements. Currently, CDEG exists as a beta version that can be downloaded from this web page.

Note that CDEG requires X11 to be already installed in order to run on Mac OS or Unix/linux systems.  X11 is optional but installed by default in recent versions of Mac OS X.

CDEG is free software, released under the terms of the Gnu Public License, version 3, as published by the Free Software Foundation.

You can download:

Please let me know if you are using this program, and especially if you find any bugs! If you find bugs please send a transcript of the session in which the bug occurred to me at  Thanks for trying it out!

My other publications relating to CDEG can be downloaded from my research page.

Nathaniel Miller <>