I've been using YAML for storing CAD data for a while now. I use it to store simulation and design information about electrical designs.

Mostly YAML works but I have seen it get fooled by some of the data that I have tried to store.

I use YAML to serialize large perl data structures into files. I will probably change from using YAML to something more reliable, at least for complex data structures. XML is the leading candidate.

There are some very interesting ideas that would be useful for CAD in Higher Order Perl.

I don't agree that perl 5 is unsuitable for writing CAD tools. At least one company sells a very large perl program that is a full-featured CAD tool.

Since such a large percentage of CAD work is really data munging, it tempting to just write the whole thing in Perl.

I have run into a fundamental problem with perl and CAD, though. Perl ruins the accuracy of floating point numbers at about 16 digits when numbers get stringified. Many things can trigger stringification, so it is difficult to prevent it from happening.