1. A method for maintaining a state for a user session with a web system, comprising: receiving a request from a user that initiates a user session with the web system; processing the request and providing a web page to the user using one of a plurality of web system engines; storing a single set of session data representing a state of the user session in a global session server, the global session server accessible by the web system engines such that the web system engines can share the session data; and for each subsequent request associated with the user session: receiving the subsequent request; retrieving the session data from the global session server using one of the web system engines; processing the subsequent request at the web system engine using the session data to provide a web page to the user; changing the session data to reflect the processing; and updating the single set of session data in the global session server according to the changed session data.