It is an interesting question. I'd like to see what HNers think about it. Personally, I would think that offering dev services or tutoring (sencha, red hat, SPServices, etc.), restrictive licensing (Green sock, sencha again, neo4j) would be more likely to self-sustain than payment offerings (donations, crowdsourcing, etc). I guess a good company to watch is famo.us since they are currently making the rounds after being funded.