[rmc]

> the obvious meaning for the expression “open source software”—and the one most people seem to think it means

I disagree. I think if you ask nearly people who know what the term "source code" means, if you ask them what "open source" means, they'll give the OSI definition (which is in practice the same as the FSF's 'free software' definition). They'll say it's more than "I can look at the source", but includes the rights to share and build on it.

Microsoft tried the term "Shared Source", which might be what you mean.