TeXCAD is a program for the PC which enables the user to draw diagrams
on screen using a mouse or arrow keys, with an on-screen menu of available 
picture-elements. Its output is code for the LaTeX picture environment.
Optionally, it can be set to include lines at all angles using 
the emTeX driver-family
\specials.
TeXCAD is part of the emTeX distribution.
A Unix port of the program exists, graphics/xtexcad/xtexcad-2.4.tar.gz