Osprey is a software platform for visualization and manipulation of complex interaction networks. Osprey builds data-rich graphical representations that are color-coded for gene function and experimental interaction data. Mouse-over functions allow rapid elaboration and organization of network diagrams in a spoke model format. Osprey also allows for user-defined large-scale datasets to be readily combined for comparison of different methods. In addition to this, Osprey is linked to the GRID and comes rich with annotation and interaction data for many commonly studied organisms, such as Yeast, Mouse, Human, Zebrafish, Rat, S. Pombe, Worm.