Xyce is an open source, SPICE-compatible, high-performance analog circuit simulator, capable of solving extremely large circuit problems by supporting large-scale parallel computing platforms. It also supports serial execution on all common desktop platforms, and small-scale parallel runs on Unix-like systems. In addition to analog electronic simulation, Xyce has also been used to investigate more general network systems, such as neural networks and power grids. In providing an Open Source version of Xyce to the external community, Sandia hopes to contribute a robust and modern electronic simulator to users and researchers in the field.