Grothendieck's last mathematical work is a 1976 pages long manuscript entitled 'Les Dérivateurs', written between October 1990 and the first half of 1991. It was meant as a foundation of homotopy theory based on the notion of derivator, which had appeared earlier in 'Pursuing Stacks'. As with many other concepts introduced by Grothendieck, derivators have proven useful in other fields of mathematics, e.g. the mysterious derived category of a ring can be characterized by a universal property if regarded as the base of a triangulated derivator. The aim of this talk is to introduce derivators and their applicability, including connections with K-theory and some open conjectures (if time allows).