> No other professional field I know of lets workers invent and alter their own tools, collaboratively, for free, and share them for free with all their colleagues.
Blacksmithing, metal working?
To a point, although you can't make your own kiln for free. The tools in those trades consume a significant amount of resources, where computing is basically free once you pay for the hardware. Something like GCC is the software equivalent of a steel mill. Even if you could design one and give out the designs for free, you'd still have to pay for the raw materials to construct one.
Did I miss blacksmiths gaining the ability to infinitely duplicate and teleport their finished pieces into people's hands? Can one learn this power?