Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. z/VM is the current version in IBM''s VM family of virtual machine operating systems. z/VM was first released in October 2000 and remains in active use and development as of 2009[update]. It is directly based on technology and concepts dating back to the 1960s, with IBM''s CP/CMS on the IBM System/360-67 (see article History of CP/CMS for historical details). z/VM runs on IBM''s zSeries, System z9 and System z10 computers. It can be used to support large numbers (thousands) of Linux virtual machines. On July 7, 2009, IBM disclosed that z/VM Version 6.1 is scheduled for general availability in the fourth quarter of 2009. z/VM Version 6.1 will require z/Architecture 2 (ARCHLVL 3), implemented in IBM''s System z10 models.