On Tue, Feb 28, 2012 at 10:40, Matthew Knepley <knepley@gmail.com> wrote:
Right now, DMs wrap up
 - Domain Topology 
 - Domain Geometry

These are nowhere in the DM interface.
 
 - Modeling approximation (like function spaces, projectors)

This is only in the DM interface through coarsening and interpolation.
 
 - Modeling equations (including decompositions, variable substitutions)

This is only in the DM interface with collective semantics. (For nonlinear ASM, I would be in favor of getting a subdomain DM which would have collective semantics on the subcommunicator instead of putting "local" evaluation into the public interface.)
 

and I may have forgotten some stuff. That is a huge amount of crap for one object.

You seem to be confusing the DM interface from a particular way of packing data into an implementation of DM.