The Stanford Information Networks Group (SING) researches computer software systems and networks that interact with or simulate the physical world. This includes sensor networks, operating systems for low-power wireless devices, wireless protocols and architectures, new wireless transciever designs, 3-dimensional virtual worlds, mobile phone operating systems, and software for physical simulations in the computing cloud. We strive to research, develop, and release open source software that other people can easily use. Software we've developed has tens of thousands of users. Protocols we've developed have formed the basis for Internet standards for connecting physical objects to the Internet.