 Quillen spectral sequence

The Quillen spectral sequence is a tool used in homotopy theory and algebraic topology, specifically in the context of derived categories and model categories. It arises from the study of the homotopy theory of categories and is used to compute derived functors. ### Context In general, spectral sequences are a method for computing a sequence of groups or abelian groups that converge to the expected group, effectively allowing one to break down complex problems into simpler parts.