[cesarb]

> There’re quite a few mechanics they use for that. The oldest one, call a special API function on startup [...]

Isn't the oldest one... to have the API/ABI version in the name of your DLL? Unlike on Linux which by default uses a flat namespace, on the Windows land imports are nearly always identified by a pair of the DLL name and the symbol name (or ordinal). You can even have multiple C runtimes (MSVCR71.DLL, MSVCR80.DLL, etc) linked together but working independently in the same executable.

[rcxdude]

Linux can do this as well, the issue is that just duplicates how many versions you need to have installed, and it's not that different in the limit from having a container anyway. The symbol versioning means you can just have the latest version of the library and it remains compatible with software built against old versions. (Especially because when you have multiple versions of a library linked into the same process you can wind up with all kinds of tricky behaviour if they aren't kept strictly separated. There's a lot of footguns in Windows around this, especially with the way DLLs work to allow this kind of seperation in the first place).