everyone.
In characteristic 0 we have a good theory of D-modules. In particular, we have a formalism of Grothendieck's six operators in the derived category of holonomic D-modules and Riemann-Hilbert correspondence.
In characteristic p>0, to my best knowledge, the proper notion that can replace 'D-module' is the stratified sheave (a sheave over the ring of Grothendieck differential operators). However I can't find much references on this topic.
So my question is: Is there a good theory of stratified sheave (parallel to the theory of D-modules)? In particular, a formalism of Grothendieck's six operators and Riemann-Hilbert correspondence.