Hercules

Enhanced Definition

An open-source software implementation of mainframe hardware that allows mainframe operating systems (MVS, z/OS, z/VM, etc.) to run on commodity hardware including x86 servers and personal computers.

Key Characteristics

- Complete mainframe CPU emulation
- S/370, ESA/390, and z/Architecture support
- Runs on Windows, Linux, macOS
- Device emulation (DASD, tape, network)
- Free and open-source
Emulated Components:
- CPU: Complete instruction set emulation
- Storage: Memory management and virtual storage
- I/O: Channel subsystem and devices
- Console: System console and operators console
- Networking: TCP/IP and SNA support
Supported Operating Systems:
- MVS 3.8j (public domain)
- z/OS (with appropriate licensing)
- VM/370 and z/VM
- VSE and z/VSE
- Linux on System z
- Learning mainframe technologies
- Development and testing
- Legacy application preservation
- Education and training
- Hobbyist mainframe computing

Use Cases

- Mainframe skills training
- Application testing and development
- Historical system preservation
- Low-cost mainframe experimentation
- Academic research