In this note some recent developments in the study of homology in semi-abelian categories are briefly presented. In particular the role of protoadditive functors in the study of Hopf formulae for homology is explained.
Gran, M., & Everaert, T. (2015). Some aspects of semi-abelian homology and protoadditive functors. Journal of Generalized Lie Theory and Applications, 9(238), 1000238. https://hdl.handle.net/2078.5/190497 (Original work published 2015)