Hercules Emulator
	The Hercules emulator provides support for running IBM mainframe software on a PC-style system, such as Linux or Windows. Hercules can run software from S/360, S/370, S/390 and zArchitecture. Visit the Hercules homepage at conmicro.cx for the current version of software and documentation.
	There are various communities dedicated to the discussion of issues relating to Hercules: The Hercules main list for general Hercules issues. The H390-MVS list for MFT, MVT, MVS, OS/390 and z/OS issues. As a practical matter, H390-MVS mostly concentrates on MVS38j. The Turnkey MVS list for issues relating to Volker Bandke's Turnkey MVS (3.8J) offering. And various others listed on the Hercules Links page.
	Quite a number of operating systems run under Hercules.  First, the major public domain operating systems: MVS 3.8J - the final public domain version of MVS. Although I don't believe IBM is issuing no-charge licenses for MVS 3.8J anymore, some users still licensed it and that's the way I'm running it. MVT - the final public domain version of OS/360. Linux - the S/390 and zArchitecture GPL'd GNU/Linux. There are also public domain versions of OS/VS1 , VM/370 and DOS/VS . I believe source code is available for many if not all of the public domain operating systems, which represents a tremendous educational opportunity. For a real bargain, you can order the public domain operating systems from the CBT tape site.  CBT also hosts some older versions of the CBT tape from the era when these operating systems were current. Finally, there are licensed operating systems such as OS/390 and z/OS. While they can run under Hercules, if you are interested in running them I recommend you contact IBM for their licensing terms before doing so.