MVS, which stands for Multiple Virtual Storage, is one of the oldest operating systems developed by IBM and distant relative to what we nowadays call DOS. MVS has its own language, JCL (job control language). Three decades after MVS was created (1974), JCL is still heavily used. As a matter of fact, where I work some programmers still use JCL on a daily basis in the z/VM system. Some of the applications where I work query VSAM files and third party application handle screen scraping to replicate the screens and output to ASP or JSP. After over forty years, the mainframe is still king.

The following table shows the history of MVS. The information below was taken from the book Understanding Operating Systems by Ida Flynn and the IBM website.

Year	System	Operating System
1964	IBM 360	OS/360
1967	IBM 360	OS/MFT (Multiprogramming with Fixed number Tasks)
1968	IBM 360	OS/MVT (Multiprogramming with Variable number Tasks)
1972	IBM 370	SVS (Single Virtual Storage) OS/VS1 (Virtual Storage 1) OS/VS2 (Virtual Storage 2)
1974	IBM 370	MVS (Multiple Virtual Storage)
1981	IBM 370	MVS/XA (MVS with Extended Architecture)
1985	IBM 370	MVS/ESA (MVS with Enterprise System Architecture)
1990	System/390	MVS/ESA
1996	System/390	OS/390 (Open Server 390)
2000	zSeries	z/OS 64-bit
2004	zSeries	z/VM

Most people do not have access to a mainframe. You can run Hercules, which emulates a mainframe environment on your computer. Cygwin must be installed to run this application on Windows.