1. A system for hosting versioned web services, the system comprising: a deployable module for implementing a web service, the deployable module comprising: a supported interface version comprising a description of service interface characteristics of the web service; and an implementation version for supporting the interface version, said implementation version comprising version metadata describing the supported interface version supported and any set of other compatible supported interface versions; a versioned implementation module for supporting concurrent deployment of multiple versions of the deployable module; and a service proxy for a version group, wherein the service proxy is a local gateway to a collection of implementation versions of the web service and provides a target destination for service interface requests for all versions of the web service; wherein the service proxy is configured to: receive the service interface request from the version group, the request comprising the version metadata describing the supported interface version of the requested web service; parse the service interface request; extract the version metadata from the parsing step; dynamically map the supported interface version from the extracted version metadata to the implementation version at the target destination; and dynamically route the service interface request to the target destination.