Getting funding for an open source technology

I was thinking if anyone has any experience with raising money to fund an open source project/technology?

Personally I think that investors might be more hesitant in making such bet. Unlike other startups where you can iterate fast and push changes out quickly to the users (say it's a web app), development of OSS seems to be much slower and you need some sort of code stability before it can be used by other people, which increases the time period for potential ROI, if any.

I appreciate all comments, ideas and contacts :)