You’re probably referring to Fundraising / Wordpress model
I checked a few and we didn’t qualify for any of them. Those umbrella non-profits often have application requirements we do not fulfill (and often cannot easily reach either). Most commonly it’s a minimum age of twelve or eighteen months of a project, being live for a certain time, being a major project et cetera.
Either way there’s usually something that has to attach to these organisations in the first place. I.e. they don’t forward money to people but to other organizations. What they do offer is being a “middle-man” to be able to accept tax-deductable donations. Meaning they offer to use their non-profit status to accept and relay donations which donors can deduct from their taxes.
The second thing they offer is credibility towards donors. Specifically the trust, "they handle donations for Postgres and Debian, this Codidact thing will not be a total sham." That is also the reason why they all seem careful in accepting new projects into the fold. They risk the trust they project outwards if they invite projects that are too strange.
That leaves us still with the task to actually found some kind of legal entity that can attach to these umbrella organizations. So while PostGreSQL is an SPI associated project that’s really just for the donations. There’s still the “The PostgreSQL Global Development Group” which seems to be the core development group and the “PostgreSQL Community Association of Canada” which is the registrant organization of postgres.org.
I’m not an expert in US legal entities, in Germany the most likely candidate would be an e.V. (a “registered association”; that’s the same thing sports clubs start out as usually).
Basically what you need to found one is seven people, bylaws, a meeting and around 100€ (court fees, notarial fees, entry into association register). That creates a juristic person which can act for all the other stuff, apply for membership in these umbrella organizations on so on and so forth.
Such a registered association is tax exempt up 35000€ revenue and up to 5000€ of profit from day one. Meaning the association doesn’t have to pay taxes up to that amount, that does not mean that it is an actual non-profit yet. Like in the US that is only the case after the tax office approves it.
At some point we will have to just found this (or something like this).