How many open source projects are 'open' in the sense of being interoperable with other software systems? Coming up with a conforming common standard is a non-starter IMO.
They tend to be 'silos of automation'.
Interoperability is a characteristic of a product or system, whose interfaces are completely understood, to work with other products or systems, at present or future, in either implementation or access, without any restrictions.
e.g. Quantlib, Boost etc.?
That's not what "open" means although having unrestricted access to the code certainly means the interfaces are completely understood (unlike proprietary software).
It would seem that Microsoft is a far worse silo with far less interoperability than most open source projects.
Of course you are right; open source is not a whole of things. Here it what is:
Open-source software (OSS) is computer software with its source code made available with a license in which the copyright holder provides the rights to study, change, and distribute the software to anyone and for any purpose. Open-source software may be developed in a collaborative public manner. According to scientists who studied it, open-source software is a prominent example of open collaboration. The term is often written without a hyphen as "open source software".
No mention of interop, which is my thesis. i.e. it is silent on the topic of interop. In fainess, it is not a requirement.
I think that was true in the 90s. But you probably are not aware of developments in MS the last few years. You might be surprised.
Personally, I have no interest in smart phone interop, so no need starting a brush fire,
Back to topic: how many open-source codes are interoperable? (btw there is a precise definition, so I won't give a link)?