  We provide and study an equivariant theory of group (co)homology of a group G
with coefficients in a gamma-equivariant G-module A, when a separate group
"gamma" acts on G and A, generalizing the classical Eilenberg-MacLane
(co)homology of groups. Relationship with equivariant cohomology of topological
spaces is established and application to algebraic K-theory is given.
