I discuss the implications of programmable wide-area networks on programming language features and design. Wide-area networks (WANs) provide a fundamentally different computational infrastructure than local-area networks (LANs). As with the switch from mainframes to LANs, the semantic difference of WANs will eventually be reflected in programming language features. The spread of LANs in the 70’s and 80’s produced client-server computing and distributed object-oriented programming. The spread of WANs demands new advances including, for example, mobile secure computing.