Leonard Kleinrock published the first paper on packet-switching theory in the RLE Quarterly Progress Report while at MIT in 1961. He established the Network Measurement Center at UCLA and worked in the area of digital networks. He also published a comprehensive look at digital networks in his book “Communication Nets.” He developed the ARPANET network with Lawrence Roberts. In 1969, Kleinrock’s NMC team connected an SDS Sigma 7 computer to an Interface Messenger Processor, creating the first node on the ARPANET, the first computer to connect to the Internet. Kleinrock’s team used the early system to iron out the initial design and performance issues on the world’s first packet-switched network. (Pioneer/Originator.)