dolfin  2016.1.0
About: DOLFIN is the C++/Python interface of FEniCS, providing a consistent PSE (Problem Solving Environment) for ordinary and partial differential equations incl. FINite element computation (depends on PETSc).
  Fossies Dox: dolfin-2016.1.0.tar.gz  ("inofficial" and yet experimental doxygen-generated source code documentation)  

DOLFIN Programmer's Reference

This documentation is automatically generated each night for the current development version of DOLFIN.

A good starting point is the graphical class hierarchy.