They are typically associated with mainframe and minicomputer operating systems. IBM's DB2 dominates the mainframe database market. Users communicated using systems developed for specific mainframe computers. They combined to dramatically undermine IBM's core mainframe business. He created the animation on an IBM 7090 mainframe computer. Terminals used for interacting with mainframe systems were gradually replaced by personal computers. CP/CMS formed part of IBM's attempt to build robust time-sharing systems for its mainframe computers. IBM received the vast majority of mainframe revenue. "APL2" for IBM mainframe computers is still available. Linux allows users to take advantage of open source software combined with mainframe hardware RAS. Server-based systems similar to the earlier mainframe systems were developed. RPG III was also available for larger systems including the IBM System/370 mainframe running OS/VS1. In 2012, NASA powered down its last mainframe, an IBM System z9. An example from IBM Mainframe and VAX highlights this concept. Equipment is available that accepts a data stream from a mainframe computer.