Comment by jpetso

Phabricator had its task tracker open to everyone, but the company behind it would charge for prioritization of tasks being tackled. If you want your bug fixed or feature implemented before whatever else is on the maintainer's inherent priority list, pay up. IIRC, they also did all development in-house without accepting merge requests from the outside, but I may misremember.

It's unclear how successful they were with this. Phabricator lasted for about a decade before announcing the end of its development, not all of which was as a stand-alone company. The announcement didn't say why they stopped.