I don't know if it had a name but the elementary school I went to had no grades, no homework, and during the school day you could work on any subject you wanted on your own time. I did manage to have two friends whom I followed around all day long, so I managed okay, and there were some good things about it, like the freedom, but on the whole I think I found it kind of chaotic and I would have preferred knowing what I was supposed to do.
Also when first started, in the second grade, I didn't speak English and had to learn quickly and that was quite stressful, both not ever knowing what was going on because everything was so loose and also not knowing the language.