[_ck_]

0.9 was the product of a few years of development and debugging 0.7 and 0.8

It powers several thousand forums. It’s stable.

1.0 is NOT just 0.9 with more bug fixes. It is a 50% different program with a 90 degree change of direction made suddenly by Matt deciding to make bbPress use the WordPress core (ala BackPress) in January 2008. It was re-engineered in just a year after a massive amount of work mostly by Sam. The alpha, beta and RC stages for 1.0 were rushed, apparently on purpose in some cases.