I do not doubt this: > Most open source software is written by programmers who are full-time employed by companies which directly consume the software, at the explicit or implicit blessing of their employers. It is not charity work, any more than they charitably file taxes. But I wonder how many important Open Source projects were started that way, by employees of companies which wanted to use those projects. Linux,…
1) Most open source software written and released today
2) Most open source software you use
The code in category #2 is much older on average.
Most people here use bash every day, but as far as I can tell, there's about one person behind it, who doesn't get paid for it (Chet Ramey).
And you're right that a lot of projects start free, and then get commercial contribution once they are valuable. Linux, git, hg, and Python all fit that profile.
In the "non-company" category, I would put Linux, git, hg, gcc, Apache. A lot of people still use Apache. nginx was in this category too until very recently.
SVN is interesting because it was started by a company (CollabNet), but I believe they diverged and the company no longer had much economic interest in it.
Anyway, I guess what I'm saying is that the story is really complicated. It's not as simple as what's in that Tweet.