To be fair, our industry brought this on itself -- we did use "master" and "slave" together as technical terms in various contexts. Now even the innocent uses of "master" that don't involve any reference to slavery are tainted too, at least from the perspective of a non-technical outsider. I'm sure their eyes will glaze over well before one can finish explaining what a version control system is, why you would want one, why it has branches and what they are used for, and that all this involves no references to slavery.