From the OP (emphasis added): > Originally (in the days of Linux 1.x / 2.0) Linux attempted to be binary compatible to existing Unices on common hardware (the

From the OP (emphasis added): > Originally (in the days of Linux 1.x / 2.0) Linux attempted to be binary compatible to existing Unices on common hardware (the personality(2) system call is also part of this). As time passed, compatibility with other Unices became mostly a non-issue – but now we do need to maintain binary compatibility with older Linux binaries…