Just what is “open,” anyway?

Here’s something I spend a lot of time thinking about: What constitutes “real” open source? Not just the license, I think the OSI has done just fine in defining an open source license. (And the GNU/FSF folks have done just fine in defining a Free software license as well.)

I’m asking, what constitutes a real open source project? What are the specific things you need to say “yep, this is a genuine open source project that really deserves the title”?

Curious what other folks think. It probably comes as no surprise that I don’t consider a project “open” just because there’s a public repository with code that is under an OSI-approved license.

Also curious of any bodies like the OSI have working definition. So many projects and companies lay claim to open source, but I see very little of it in practice.