Symm's equation is a first-kind integral equation for computing conformal m
aps of simply connected regions. The package CONFPACK solves Symm's equatio
n by an indirect boundary element method using an accurate corner represent
ation. This solution technique is extended here to include nonoverlapping d
omain decomposition. Degrees of freedom are introduced on one or more inter
faces and different unknowns are used, leading to a system of second-kind e
quations. The corresponding linear system can be expressed in Schur complem
ent form. The accurate treatment of corners is preserved in the new formula
tion. The results of serial and parallel MATLAB implementations of the new
algorithm show significant speedups as the number of unknowns grows.