The deployment and management of differing versions of software components can be simplified. External interfaces of the component can remain constant in behavior while the internal logic, and possibly internal storage, can change between versions. Such a version management system can be transparent to the client programs, since interfaces can remain backwards compatible between component versions. This transparency can greatly reduce the risks of unpredictable behavior or system failure. A system can maintain each version of a software component, and can use a dispatch technique to determine and instantiate the currently active version whenever a client requests a service from the software component during a session. Old instances, possibly of other versions, can be maintained as long as required on the server. Such systems can apply to stateful and stateless components, using synchronous or asynchronous communications, and which may communicate over networks and may use web services type protocols. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.