Successor versions of an application service provision runtime library of an application service provision apparatus are provided with corresponding update services to facilitate upgrade of applications to selected ones of the successor versions on request. In various embodiments, a dispatcher of the application service provision apparatus is provided with complementary functions to coordinate the servicing of the upgrade requests. In some embodiments, each of the update services is equipped to upgrade the application from an immediate predecessor version of the runtime library. In other embodiments, each of the update services is equipped to upgrade the application from any predecessor version of the runtime library.