  We will show make two contributions to the theory of effective Kan
fibrations, which are a more explicit version of the notion of a Kan fibration,
a notion which plays a fundamental role in simplicial homotopy theory. We will
show that simplicial Malcev algebras are effective Kan complexes and that the
effective Kan fibrations can be seen as the right class in an algebraic weak
factorisation system. In addition, we will introduce two strengthenings of the
notion of an effective Kan fibration, the symmetric effective and
degenerate-preferring Kan fibrations, and show that the previous results holds
for these strengthenings as well.
