Remote execution of some part of the program - failure must lead to total failure of program. Remote use of floating point hardware - failure might map to local emulation rather than total failure. Remote name service (e.g. yellow pages) - failure to get an answer (timeout) might map to retry (typical behavior with multicast idempotent services). Load sharing systems (e.g. ESA Telemetry monitoring and analysis systems). Distributed authoring systems through E-Mail.