IXS
(Integrated XSeries Server) An IBM System x server that plugs into a Power Systems computer. Running Windows or Linux, the IXS shares disk storage, server management and user administration with its host. The Integrated xSeries Adapter (IXA) attaches up to 60 System x models.
FSIOP-> IPCS-> INS-> IXS
IXS started life in the days of the 486 CPU as the FSIOP (File Server I/O Processor), then IPCS (Integrated PC Server), INS (Integrated Netfinity Server) and subsequently the IXS. See Power Systems and System x.