“What Goes into Making an OS to Be Unix Compliant Certified?”, Terry Lambert2022-01-14 (algorithms; backlinks)⁠:

I was the tech lead at Apple for making Mac OS X pass UNIX certification, and it was done to get Apple out of a $296.05^$200₂₀₀₆M lawsuit filed by The Open Group, for use of the UNIX™ trademark in advertising…The options were: 1. Make Mac OS X actually UNIX™, to defang the lawsuit; this would also make The Open Group industry relevant, when at the time they were losing a lot of that to Linux’s increasing popularity—which is why it was an option on the table at all.

[Because Mac OS X is layered on top of Darwin, based heavily on Mach+BSD, and most Unix/Linux software works reasonably well on it, one might assume that this would not be that hard or be pro forma. But in an example of Hyrum’s law, improving Unix standards conformance breaks everything due to bit creep on the differences between Mac OS X & Unix…]

…I was given the “go”. And so we ran the compliance test suite against the existing Mac OS source base, and it immediately errored out because of the header files.

And Ed Moy and I made a 2 line change that moved a type definition from stdio.h to where it was supposed to be, instead. One line of change in stdio.h, and another in the file the type was actually supposed to be located in. And we ran the tests again, and one of the header file errors in the tests went away.

So we did a “world build”, where everything that was in Mac OS X, including iTunes, got rebuilt. That—essentially, one line change—broke 152 (from memory; that number sticks up, but it might have only been 137) projects failed to build. Including iTunes.

…We were promised 1⁄10^th of the $296.05^$200₂₀₀₆ million, or $29.6^$20₂₀₀₆ million in stock, on completion. $14.8^$10₂₀₀₆ million to me, $7.4^$5₂₀₀₆ million to Ed, and $7.4^$5₂₀₀₆ million to Karen Crippes, who was looking for a home in Mac OS X development, I knew was an amazing engineer, and who could be roped into being technical liaison and periodically kicking off the tests and complaining to Ed and I about things not passing. I got the $14.8^$10₂₀₀₆ million, because it was going to be my job on the line, and potentially, my ability to work in industry at a high level, ever again, in the future…It was going to be long slog.

…We had a lot of gratitude in the Open Source community—particular for our fixes to make bash pass the tests. You have absolutely no idea how much Apple contributed to the Open Source community, as part of this project, because it was a secret project—at least to people outside Apple—so we didn’t advertise the fact. But I expect we contributed about 2 million lines of code, to hundreds of Open Source projects, over the course of that year. A lot of gratitude—but it wasn’t collective, and so Apple was still faulted for “using Open Source code, but never contributing back”. We fixed at least 15 major gcc bugs, for example. You have no idea.

Backlinks: