Reposted from IBM's internal VM forum. VM is now a 30 year old operating system, and if you consider the groundwork laid by CP-67 and CP-40, it's almost 40 years old! Hard to believe!
VM/370 Release 1 was announced on August 2, 1972. The "blue letter" (announcements were printed on blue paper at the time and shipped to the branch offices for distribution to the marketing folks and customers) also announced OS/VS1 and OS/VS2. The latter were the virtual storage versions of their System/360 predecessors, OS/MFT and OS/MVT. The idea of VM was that the customer could run his production MFT or MVT system along with his new VS1 or VS2 system for testing and migration. Of course, he would also have to buy some brand new IBM hardware to do this (needed a System/370 with address translation capability). VM wasn't going to be marketed by IBM for more than a few years, until the migration period for VS1 and VS2 was over. But the customers found use for VM on its own as a production system and it became wildly popular, so here we are today (although we've come full circle with the IBM view of VM as a host for guest Linux systems). Long live VM! Tom Klensk
