Finding and/or becoming an open source product owner

Question

Are there any open source projects that have roles that would be equivalent to a Scrum product owner role? If so, how did you go about finding these examples, and how do you believe those product owner roles came to be?

(Just to be clear, it's not a requirement the project is Scrum based, just that it's open source and roles stated are equivalent to a Scrum product owner role. Also, I'm talking about a volunteer role, not a paid position at a non-profit.)