This is a difficult thing. In 2012/2013, forums are ubiquitous. If you're going to write a new forum software, you then have to make a choice: 1) Do you only t

This is a difficult thing. In 2012/2013, forums are ubiquitous. If you're going to write a new forum software, you then have to make a choice: 1) Do you only target "people who don't have a forum yet but want to start one"? 2) Or do you make an upgrade/migration path from vBulletin/etc so that you can let existing forums move to your software? If you go with #1, that's a long, long slog IMO. If you go with #2, you have an instant market of 100,000,000 forums.