1. A computer system, comprising: a processor; a memory comprising at least one computer-readable storage medium coupled to the processor; a runtime environment arranged to support execution of an application program with respect to the memory and the processor, wherein the application program is divided into a plurality of bundles and wherein each of the bundles comprises metadata that includes a definition of zero or more dependencies related to the respective bundle; and a deployment system arranged to deploy the application program into the runtime environment, the deployment system comprising a deployment management unit and one or more personality specific deployers, each personality specific deployer being separate from the deployment management unit and associated with a respective personality type; wherein the deployment management unit comprises: a personality determining unit arranged to determine whether each bundle of the plurality of bundles is a personality-specific bundle having a personality selected from among a predetermined set of personality types, or else is a generic bundle not having a specific personality; an operator unit arranged to apply one or more operations to each of the plurality of bundles, including installing each of the bundles ready for deployment; and a generic deployment unit arranged to deploy each of the generic bundles installed by the operator unit into the runtime environment; wherein the operator unit comprises a synthesiser unit comprising an extractor unit arranged to examine the metadata and extract export statements from the metadata, a converter unit arranged to convert each of the export statements into a corresponding import statement defining a respective exported package as an imported package, and a creator unit arranged to create an additional synthetic bundle comprising metadata and a class loader, insert the import statements into the metadata of the synthetic bundle, and add the synthetic bundle to the application; wherein the synthesiser unit is arranged to set a thread context class loader associated with the application in the runtime environment to delegate class loading to the class loader of the synthetic bundle, and the class loader of the synthetic bundle is arranged to load each of the exported packages of the plurality of bundles as the imported packages from the synthetic bundle; and wherein each of the one or more personality specific deployers comprises: a personality specific transformer unit arranged to transform each of the personality-specific bundles having a same personality type as the personality specific deployer by identifying one or more additional dependencies, not included in the metadata of the personality-specific bundle, that are associated with the personality type of the personality-specific bundle, and inserting the one or more additional dependencies into the metadata of the personality-specific bundle; and a personality specific deployment unit arranged to deploy each of the personality-specific bundles having the same personality type as the personality specific deployer installed by the operator unit into the runtime environment.