Multiprogramming with a Variable number of Tasks (MVT) was the most sophisticated of three available configurations of the OS/360's control program.^[1] In turn, OS/360 was an operating system for the IBM System/360 line of computers. MVT was intended for the largest machines in the System/360 family, introduced in 1964, but it did not become available until 1967. Early versions had many problems and the simpler MFT continued to be used for many years.

In later decades, MVT had been developed into MVS, then OS/390, and now z/OS.

Although officially PCP, MFT and MVT were not a separate operating systems from OS/360,^[1] those were only an install-time configuration options—in today's words, a three different variants of OS kernel—because of quite different behaviour and memory requirements, users commonly considered them de facto separate operating systems, and referred to them as early OS/360, OS/MFT, OS/MVT, respectively.

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