Allocatus Server accesses the Project Server 2002/3 database according to Microsoft's specification to read and write data from Project Server. With Project Server 2007 Allocatus uses the new Project Server Web Interface (PSI). Allocatus Server processes the data and provides it for the Allocatus Clients through its own web service interface. The Allocatus Clients use this web service and create, read, update, and delete calendar and task items in Microsoft Outlook/Lotus Notes. Because the communication is based on http/https protocols it works across the boundaries of sites and networks in large enterprise settings. The Exchange Option directly integrates with Exchange Server.