We propose the development of a set of software technologies ("SwitchWare") which will enable rapid development and deployment of new network services. The key insight is that by making the basic network service selectable on a per user (or even per packet) basis, the need for formal standardization is eliminated. Additionally, by making the basic network service programmable, the deployment times, today constrained by capital funding limitations, are tremendously reduced (to the order of software distribution times). Finally, by constructing an advanced, robust programming environment, even the service development time can be reduced. A SwitchWare switch consists of input and output ports controlled by a software-programmable element; programs are contained in sequences of messages sent to the SwitchWare switch's input ports, which interpret the messages as programs. We call these "Switchlets". This accelerates the pace of network evolution, as evolving user needs can be immediately reflected in the network infrastructure. Immediate reconfigurability enhances the adaptability of the network infrastructure in the face of unexpected situations. We call a network built from SwitchWare switches an active network.