The core WordPress / bbPress features broken out into their own (sort of) framework. Interesting if building something resembling WordPress but a little off-piste.
TalkPress VIP is a bbPress forum hosting service from Automattic / WordPress.com. Starts from $1'000/mth plus $1'500 setup. Application process, not all sites accepted, like WordPress.com VIP.
A bbPress theme browser from bbPress Showcase.
bbPress showcase is a site dedicated to showcasing the power of bbPress (the forum software from WordPress developers).