What the heck is a BOF?
BOF is short for "Birds Of a Feather" and comes from the saying "Birds of a feather flock together". This means that people with similar interests come together to talk. An informal discussion group, scheduled on a conference program or formed ad hoc, to consider a specific issue or subject. It is not clear where or when this term originated, but it is now associated with the USENIX conferences for Unix techies and was already established there by 1984. It was used earlier than that at DECUS conferences and is reported to have been common at SHARE meetings as far back as the early 1960s.
At UbuntuConferences there are many BOFs. They generally begin with a development idea, and refine it into a specification.