Linux kernel development is also primarily[1] done by paid engineers [1] http://www.linuxfoundation.org/news-media/announcements/2012/04/linux-foundation-relea

Linux kernel development is also primarily[1] done by paid engineers [1] http://www.linuxfoundation.org/news-media/announcements/2012/04/linux-foundation-releases-annual-linux-development-report http://www.linuxfoundation.org/news-media/announcements/2012...