  We introduce the notion of Glanon groupoids, which are Lie groupoids equipped
with multiplicative generalized complex structures. It combines symplectic
groupoids, holomorphic Lie groupoids and holomorphic Poisson groupoids into a
unified framework. Their infinitesimal, Glanon Lie algebroids are studied. We
prove that there is a bijection between Glanon Lie algebroids and source-simply
connected and source-connected Glanon groupoids. As a consequence, we recover
various integration theorem and obtain the integration theorem for holomorphic
Poisson groupoids.
