I don't know about OS X. You're right about Linux, though, and Torvalds will descend into an angry screed if you try to break the ABI. Windows, on the other han

I don't know about OS X. You're right about Linux, though, and Torvalds will descend into an angry screed if you try to break the ABI. Windows, on the other hand, does not save the numbers between releases. http://j00ru.vexillium.org/ntapi_64/ http://j00ru.vexillium.org/ntapi_64/ is a table showing the system call table for each given release, and how sometimes it even changes between service packs of the same released OS.