Apart from having a framework/service for funding open source projects, we need about the people who develop the dependencies used in those projects.

Project maintainers should have the ability to 'forward' part of the received donation to other projects - without which the project wouldn't have been possible.

Which contributors, which dependency and how much to share - these questions are best answered by the project maintainer(s) - they can forward zero or all the funds and make the process automatic, so when a donation is received, the system automatically redistributes it to other accounts, as configured by the maintainer.

I've worked on a design spec for such a system some time ago: https://github.com/boomhub/design

I'd gladly resume work on it if anyone else feels like this is the good way to go. Just start by creating an Issue :).