A cottage is the perfect place for Cairn!

This is a good answer. As the blogpost says, I would separate the NSR design community and the NSR philosophy into two related but distinct categories; essentially what @Enfors@lemm.ee suggested is correct. Cairn for example is very much an “OSR game” in that it focuses on lethality, problem solving, critical thinking, emergent narrative, and so on. But it eschews B/X compatibility (not even close!).