A system comprising: a computer system that is in electronic communication with one or more clients, the computer system including a plurality of servers, and an engine adapted to be executed by the one or more clients to select a target server or server subset among the plurality of servers, using a client application identifier, which client application identifier is associated with a particular application of a particular client or group of particular clients; the system being characterized in that the engine includes a service mapping subsystem configured to map each client application identifier to the target server or server subset; wherein the engine is configured to receive information indicative of identities of servers that provide a desired application and to generate based at least in part on the information and the client application identifier, a client application identifier specific sorted list of servers that provide the desired application, wherein the sorted list comprises information that defines an order in which to attempt to contact servers until at least one functioning one of the servers is contacted; wherein the one or more clients are configured to attempt to contact the first server listed in the client application identifier specific sorted list of servers; wherein the one or more clients are configured to determine whether an answer was received from the server selected; wherein the one or more clients are configured to, if no answer was received from the server selected, attempt to contact the next server listed in the client application identifier specific sorted list of servers; and wherein the one or more clients are configured to, if an answer was received from the server selected, establish an electrical or data communication between the one or more clients and the server selected. a computer system that is in electronic communication with one or more clients, the computer system including a plurality of servers, and an engine adapted to be executed by the one or more clients to select a target server or server subset among the plurality of servers, using a client application identifier, which client application identifier is associated with a particular application of a particular client or group of particular clients; the system being characterized in that the engine includes a service mapping subsystem configured to map each client application identifier to the target server or server subset; wherein the engine is configured to receive information indicative of identities of servers that provide a desired application and to generate based at least in part on the information and the client application identifier, a client application identifier specific sorted list of servers that provide the desired application, wherein the sorted list comprises information that defines an order in which to attempt to contact servers until at least one functioning one of the servers is contacted; wherein the one or more clients are configured to attempt to contact the first server listed in the client application identifier specific sorted list of servers; wherein the one or more clients are configured to determine whether an answer was received from the server selected; wherein the one or more clients are configured to, if no answer was received from the server selected, attempt to contact the next server listed in the client application identifier specific sorted list of servers; and wherein the one or more clients are configured to, if an answer was received from the server selected, establish an electrical or data communication between the one or more clients and the server selected. <EOS>