Energy decomposition analysis (EDA) is a theoretical framework that quantitatively analyzes intermolecular interactions and reveals their physical origins through numerical insights. Since its introduction in 2014, the generalized Kohn-Sham EDA (GKS-EDA) method has emerged as a robust family based on KS-DFT calculations. This chapter systematically presents the GKS-EDA family for various intermolecular interactions with a focus on its applications to complex systems including spin states, excited states, and environment effects.