|Don't ask to ask, just ask|
The beauty of this concept is the leverage of existing tools (modern filesystems, versioning, perl/tk, etc.) to provide an elegant example of what is now possible but rarely implemented.
With CVS, multiple authors can work on a single CAD project complete with real time display of all changes as they happen.
Each element of the drawing (an object perhaps; line, circle, etc.) can be described in a simple and human readable text file:
Groups of these files make an application which can later be used as a reference, providing object oriented approach to CAD design.
Making the hard things possible...
The author makes these points clear in about "400 lines of perl code." I downloaded the proof of concept application, installed the few modules necessary and it worked perfectly on my Fedora FC2 box. The concepts demonstrated in perl may not provide for the needs of a commercial CAD application and the author states (in various POD comments) that perl is not the solution for long term CAD implementations.
What is profoundly important are the concepts demonstrated. Faced with thousands of text files, perl was the natural solution for parsing and display of this information. With a bit more work, I am certain this proof of concept could surprise more than I with the possibilities of perl/tk and GUI applications to visual data display.
The first dog barks... all other dogs bark at the first dog.
In reply to Open Human Readable Computer Aided Design file format by SciDude