[tiffanyh]

This old thread has former Y! folks chiming in as to why.

https://news.ycombinator.com/item?id=10558288

> I think the justifications were better support for running on Linux (storage drivers, Java, MySQL, oracle), better support for virtualization (although bsd jails are better than virtualization in my opinion, and a better fit for Y!), and it would be easier to support one os instead of two and acquisitions (including inktomi) really wanted to run on Linux.

[znpy]

Interesting, from that links i see some replies like this:

> Also, the FreeBSD license was more relaxed and commercial products (like NetAPP) could include and extend FreeBSD without disclosing their modifications.

and then (same comment):

> Our frustration with lack of support for FreeBSD moved us to choose Linux and Windows

I think these two things are strongly correlated: the bsd license allow companies to avoid contributing back improvements, and this prevents the main FreeBSD codebase from getting better.

I think that in the long run this is detrimental to projects.