What forum software would you say is among the most unpopular? And no, vBulletin 5 is not a valid answer to this question, so don't even go there. When I say unpopular I'm referring to the amount of attention that a software gets and how many people actually use it. I'm not referring to software that's unpopular because lots of people think it's crap. Popularity doesn't have to relate to quality, something can be good software but still be unpopular because it's too different from the mainstream. A good example of what I'm talking about would be Kareha, which isn't exactly a popular script outside of the *chan scene due to its functionality being a bit alien to the average forum admin.