Montessori programs, maybe?
And there are schools that lack curricula. In "Sudbury" schools, i.e. those that emulate the Sudbury Valley School, no one is given any disciplined instruction in any subject until and unless they request it. The original SVS claims that in more than four decades of their existence, all of their pupils have learned to read before leaving and 80% have gone on to colleges or universities. Schools with curricula can't generally claim those things.
I think the requirement that all pupils must learn mathematics has led to a lot of dishonesty: University graduates have been taught that mathematics consists of clerical skills to be memorized and followed algorithmically.