For software the overwhelming consensus is the OSI definition (extremely close to the FSF def, extremely close to what is applied as criteria by various distro,

For software the overwhelming consensus is the OSI definition (extremely close to the FSF def, extremely close to what is applied as criteria by various distro, etc.) You may want to write "Open Source" to be sure it is not confused with something else, but even "open source" should be parsed as that definition by default. This is not even pushing a political agenda or a judgment of value. Just "everybody" calls that like that, so there is no point in overloading the term for other approaches. Using another term for other things is perfectly fine and there are plenty of them possible with a positive tone, in case they bring positive things to the table.