А тут сегодня наткнулся на статью, в которой описано кто делает ядро linux. Цитирую:
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Morton noted that “People’s stereotype [of the typical Linux developer] is of a male computer geek working in his basement writing code in his spare time, purely for the love of his craft. Such people were a significant force up until about five years ago ...” but contributions from such enthusiasts, “is waning... Instead, most Linux kernel code is now generated by corporate programmers.” Morton noted that “About 1,000 developers contribute changes to Linux on a regular basis... Of those 1,000 developers, about 100 are paid to work on Linux by their employers. And those 100 have contributed about 37,000 of the last 38,000 changes made to the operating system.” The article later notes “Even though anyone can submit changes, rarely does good code come from just anyone. Morton noted that it is rare that a significant change would be submitted from someone who is completely unknown to the core developers. And all submitted code is inspected by other members of the group, so it is unlikely some malicious function may be secretly embedded in Linux... Far from being a project with a vast numbers of contributors, about half of those 37,000 changes are made by core developer team of about 20 individuals, Morton said.”
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Если коротко, то из 38.000 последних изменений 37.000 были сделаны всего сотней разработчиков, чья работа над Linux оплачивается работодателями. Половина из этих 37.000 изменений были сделаны командой всего из 20 человек.

Вот тебе и open source, и цена помощи разработчиков со всего мира: 20 человек на зарплате делают в 15 раз больше, чем вся open source community в одном из самых популярных проектов.