I think that for all intents and purposes the JCF is a part of J2O, not a separate site hosted on the same domain. It's linked to like any other site section on J2O, it shares most of its staff (in the sense that apart from Torkell, active JCF staff is also J2O staff), it is the primary place to discuss J2O itself (in this forum) and even the default layout is largely similar. I suppose the fact that they have distinct userbases and aren't integrated is more for historical and technical reasons than because the sites are not connected.