Sexism is not endemic to software. As far as I've seen, there's no compiler flag that declares your gender (or race, or cultural background). That's actually one of the great things about it - it's objective. Your code isn't female or Asian or Black or gay or whatever - it compiles or it doesn't, solves the problem or it doesn't.
Of course, sexism is present in software communities. It's spearheaded by the boneheads, condoned by the silent, and condemned by those who would like to see it change. And that's a fine thing.