We review the main steps of the differential equation approach to the
analytic evaluation of Feynman graphs, showing at the same time its application
to the 3-loop sunrise graph in a particular kinematical configuration.Comment: 5 pages, 1 figure, uses npb.sty. Presented at RADCOR 2002 and Loops
and Legs in Quantum Field Theory, 8-13 September 2002, Kloster Banz, Germany.
Revised version: minor typos corrected, one reference adde