The LINUX example is a very good one. Berkeley System V was a UNIX
version written by programmers and students at the Berkely between 1976 and 1979. So basically built using taxpayers money, it was free available for other universities, fine. Some parts of it were based on still older AT
&T code, and partially replaced over the years.
In the mid of the 80th it became clear that the approach used for this system, a single threaded kernel, was inefficient in all multi-user or multi-process application, more modern UNIX
implementations took over, using POSIX standards etc... and most important efficient Kernel concepts. AT
&T gave up all property rights of this ( not voluntarily, there were many lawyers involved), and it lay around in the software bin for a decade.
The big discovery by Linus Torwald was that
a) the requirements of a home computer are low, you typically only run one application
hardware has got so powerful that you can give up on efficiency - with a big enough engine everything flies
c) Microsofts Windows 95 etc weren't efficent either.
d) Nobody claimed any rights on the code he discovered under dust built in more than a decade.
So a bit of software was bundeled and a bit written and ready was LINUX - and since then got nothing but many new colorful desktops .
So, let us a build an airplane a la Linux.
It will look like a DC9, have the efficiency of the DC9, and will be built in China. There whill be a 90 seater called Gnome, a 102 seater called Geyser and a 114 seater called Giant. I hope it will be as reliable as a DC9, and not come with instructions how to crash it as normal passenger as Linux comes...