The longstanding solution to this problem is government support. This might not be a sexy solution on HN, but it is the obvious one.
Government support works when you can get a majority of the people to agree they want something enough to pay for it. It works less well when the public good primarily serves the interest of a minority. In principle, even if government support was effectively tackling all the things it was appropriate for, there could be room for Snowdrift.coop in coordinating more niche things.
Who decides how much the Postgres guys get, or if its worth to support yet another NoSQL store? Involving politics seems like a surefire way into mediocrity. How to get around that?
Obviously the government would create a class of acceptable organizations to donate too, rather than designating a single platform / portal. In this way it would be just like the new crowd equity system.
If there was a way to do so without complicating my tax filings, that would be even better.
In your example the new NoSQL store should prove itself before being funded.
Think of all the javascript frameworks appearing nowadays. How many will have a significant user base in 5 years or even still be maintained ?
You should get gov money once you are a reference in your field. Postgres and OpenSSL certainly are.