I googled "open source aircraft" today, and got quite a few hits.

It appears that open source practices and hard-engineering
(engineering that ultimately transcends from digital into physical,
unlike software) are still pretty far apart from each other. There
are several sites that refer to themselves as "open source" aircraft
development sites. Widening the search shows that there is obviously a
broad desire to adopt some of the best practices from software
engineering into other engineering disciplines.

I've seen lots of "we're hip because we are open engineering" garbage
floating around, and after much revision of the wheel, it is still not
rolling any better or straighter. I'd like to point out to anyone who
is interested, that the grain of advantage in Open Source that most
applies to other disciplines, is: effective distributed revision
control. This is what products like Bazaar, and Apache Subversion do,
and it is the primary reason why tens of thousands of hours of prior
work, can be consolidated into a single project in a matter of
minutes.

While software like Wiki's and web forums work well for indevidual
projects with simple file sharing, they do not permit cross
collaboration between unrelated projects. If aircraft design was like
software, you'd be able to take a wing design from any airplane, copy
it, make some revisions, and save it into the design of a totally
different aircraft, all without impeding the development cycles of
either the original, or the new design. (yes I know, you can do this
with some very expensive CAD software packages, but if you pay that
much for software, your not going to publish outside of the
corporation) You would also retain the option of including any new
features added at later dates to either design into the other in a
trivial way.

Note that this _is_ possible to a large degree in homebuilt aircraft
design. But only in the case that good revision control practices are
observed.

IMHO there should be NO MORE "open source" aircraft projects, until
somebody gets around to implementing a public, vendor-neutral RCS
(revision control system) for aircraft development, so that _any_
designer can submit and begin new projects and contribute to those of
friends and peers.

This is something that perhaps the EAA could sponsor?