Small data point, but we all spoke English at the first Paris Hacker Meetup ( http://parishackers.org/ http://parishackers.org/ ), since a few hackers weren't F

Small data point, but we all spoke English at the first Paris Hacker Meetup ( http://parishackers.org/ http://parishackers.org/ ), since a few hackers weren't French. This might have been biased, since most people were HN, and HN is in English... ParisJUG (Paris Java User Group) is in French, but we sometimes have foreign speakers giving talks in English. That being said, developers usually know English better, since English is the lingua franca of development.