1. A method for resource allocation management for an interactive session on a grid computing system, comprising: assigning a user class to an end user; storing the user class for the end user in a user membership directory; receiving an end user request for an interactive session with the end user after the user class is assigned to the end user; in response to receiving the end user request, generating a contract for the interactive session, wherein the contract includes a service level agreement with the end user; and allocating resources for the interactive session in accordance with the service level agreement; wherein generating the contract for the interactive session includes: identifying application programs needed by the end user to be launched in said interactive session; determining the user class to which the end user belongs by retrieving the user class from the membership directory; consulting one or more user class authorization policy files to determine resource allocation policies for the end user's user class; for each of the application programs, obtaining from an application profile for the application program. CPU and bandwidth requirements for the application program; estimating a total CPU and bandwidth requirement for the application programs from the CPU and bandwidth requirements determined for each application program and based on an order of execution of the application programs and the resource allocation polices for the end user's user class; generating the contract for the interactive session using the end user's class, the resource allocation policies for the end user's class, and the estimated total CPU and bandwidth requirement.