Bitweaver is a fork of Tiki. It was done in 2003 because some contributors thought Tiki was too bloated. They wanted to make it easier to offer alternate features (such as PhpBB instead of native forums). BitWeaver's motto is 'Packages are King', and has frequently alternative ways to do the same thing (Search and ILike, or PigeonHole and Categories) while Tiki integrates all features in the same release.
As the figures show, Bitweaver does not advertise any consultants, and has not managed to create a momentum of contributions by independent developers.