@Jeff
I think the problem is that you said “how do you tell if something that calls itself “open source” is really open source?”.
In the context of this and your other posts about your donation I guess what you mean to say is “what do the rules of this particular donation consider Open Source” but I think it is just as easily read as, well, “What is a really real open source project”. The difference, I would say, is that the former should not be upsetting to someone who consider themselves an OS project but don’t meet all your requirements, whereas the latter might be.
But assuming you meant the former, I still think you could have been more clear on the wording, perhaps in calling it an “Open Source Community Effort” (or something) donation rather than an “Open Source Project” donation, because that does seem to be the thing you are hoping to reward?
For the purpose of your donation, I think it is a fine idea that you focus on projects with a thriving community around them. But for a definition of what’s really open source, I’d say a community isn’t a requirement at all. To me, open source means that I get access to the source code, period. What I am allowed to do with the source code comes down to the particular open source licence, of course, and the whole “different flavors of free” discussion comes into play. But it can be open source even without being free in any sense at all, beer (my favorite sense) or otherwise. And it can certainly be open source without having any community, or accepting commits. The developer can have been dead for twenty years and I’m the first downloader in fifteen years - if I (legally) get the source code it is open source. Simple as that.
Now, I don’t think anyone could argue that something could be open source if you didn’t get to see the source code. Thus it feels safe to suggest that the requirement “You get to see the source code” isn’t just my personal opinion on a necessary requirement for what constitutes open source. But from there on, I think any additional requirements you throw on to the heap have to be largely of the personal opinion type. That means that when posting questions as “what is really open source” it doesn’t hurt to be extra careful in also clearly marking the scope, as in “what is open source to me” or “what is open source to this donation”.
But probably rewording to “what is a thriving Open Source Community to this Open Source Community donation” would be even better.
@Ishmael
“If you have a VC system, making it accessible over the net is so trivial that I cannot imagine why anybody would keep their VCS confined to their private network (he says, and adds after a dramatic pause: “for their OS projects”).”
Perhaps because they don’t want their little home server slashdotted should the project suddenly become popular? Setting up a subversion server turns out to be so easy even I can do it. For a long time I kept my OS projects on a server in my home, giving access over VPN to the other committer and uploading zips with the source to a public site whenever some unit tests would look greenish if looked at through the right eye of a pair of green-red 3D glasses. I agree with you that it is simple to flip the public bit on your VCS if it is already on some real host like sourceforge or berlioz (where we now keep our source) but I think I can’t be the only one with an OS project that started on some private VCS server? And sure, moving the files to a public VCS may be easy enough, but, well, you know, it’s that whole “you have to come up with a project description” stuff to go through before you get to check in your project on those public hosts…very uninviting! 
