I also checked this out some time ago. It is a great idea - but is probably only one of several solutions (and I'm sure this isn't the forum to discuss them - although it is probably better to think about them in advance). For example, it is also possible to envision a database backend where the entities are store in tables. With proper additions, any of the revision tracking is available (although branching would be difficult). I had been working on a CAD distribution a year ago that had a DB connection (sqlite in this case) as an optional backend, but have had other projects that have kept me from recent development and releases.

In a database vs CVS vs someother format discussion there are a few issues that are useful to think about.

• CVS is already very functional
• Databases are already very functional
• Various CAD formats are obviously very functional
• CVS is open, revision tracking is easy
• Database interaction is open, revision tracking is possible
• Various CAD formats are usually proprietary, revision tracking is not as easy (if even possible)
• CVS storage in this case requires one fair sized file for each entity, there is a bit of CVS overhead for checking in and maintaining drawings with thousands of lines (eventually becoming painfully slow)
• Database storage has one line per entity, with properly indexed rows, thousands of lines vs 1 line are nearly the same access time. Storage size is limited by the database engine.
• Various CAD formats have various benefits - some binary formats may be small, some text formats may be difficult to process, some XML formats may be huge - there are a host of trade offs.
• CVS storage is typically easy to access from anywhere (although checkout of huge files is a pain).
• Database storage is typically easy from anywhere (although copying files is a pain).
• Various CAD files are typically easy to access from anywhere (maintaining concurrency between documents and updating revisions everywhere is a pain).

So - which is the best solution? I would say, create interfaces that support them all. As for which you should use? Be wary - they all have pitfalls.

As for the comment "perl is not the solution for long term CAD implementations." I would revise that to say Perl 5 is not the solution, Perl 6 will be a different story.