This description of OpenFunding scenarios makes a tonne of sense:
http://ez.no/developer/articles/open_funding_the_defeat_of_dysfunctional_development/how_open_funding_works
The how-to do it is tricky. For adding core elements to MODx, it is simple and can be handled by the core development team but to involve other devs or contributers to a project would require significant value assessment. IMHO time put in doesn’t work for remuneration because it rewards people who are slower, then how do you assess the value of the individual contributions for non core developers? Stipends or honorariums, % shares or bids may work but the complexity of compensation doesn’t lend itself to a community because it encourages competition for work, money and share.
Regarding the development of addons, my personal opinion is that a combination of OpenFunding, Commercial Funding (via MODx’s founders’ company Collabpad), and ad hoc community development teams are the best scenario for MODx.
I’ve only seen one example of a feature development team in MODx (which is common in many other OS project communites) and that is the KiweeCommerce team that took over the development of a privately developed project.
There are some talented developers and designers in the MODx communities and I see many people adding to projects in threads and such but why not semi-formally form development teams to build solutions for MODx addons. Some of these may get picked up as projects by the Core Team but in any case it would advance the feature set in MODx without the complex infrastructure of a financial model.
Chip-in looks like a terrific idea but as Ryan points out, our feet are hardly hitting the ground we’re running so fast.