Inthis Paper We Advocate For Operating System Support of Ad Hoc and Sensornetworks. We Contend That Only a Network-Wide, Power-Aware Operating System Canefficiently and Fairly Manage the Limited and Timevarying Resources Inherent Inad Hoc Application Environments. We Describe Magnetos, an Ad Hoc Operatingsystem That Provides a Single System Abstraction of an Ad Hoc Network Toapplications.