The CASPER collaboration for high-performance open source digital radio astronomy instrumentation

The Collaboration for Astronomy Signal Processing and Electronics Research (CASPER) has revolutionized the cost and time scale for development of high performance radio astronomy signal processing instrumentation. We present open source designs (hardware, gateware, libraries, and software tools) for a variety of flexible high bandwidth instruments, including correlators, beamformers, spectrometers, VLBI, pulsar timing and transient search machines. The collaboration relies on a small number of modular, connectible, upgradable, hardware components and platform independent software libraries that can be reused and scaled as hardware capabilities expand.