Browse free open source Mainframe software and projects for Windows and ChromeOS below. Use the toggles on the left to filter open source Mainframe software by OS, license, language, programming language, and project status.

  • Gemini 3 and 200+ AI Models on One Platform Icon
    Gemini 3 and 200+ AI Models on One Platform

    Access Google's best plus Claude, Llama, and Gemma. Fine-tune and deploy from one console.

    Build generative AI apps with Vertex AI. Switch between models without switching platforms.
    Start Free
  • Try Google Cloud Risk-Free With $300 in Credit Icon
    Try Google Cloud Risk-Free With $300 in Credit

    No hidden charges. No surprise bills. Cancel anytime.

    Use your credit across every product. Compute, storage, AI, analytics. When it runs out, 20+ products stay free. You only pay when you choose to.
    Start Free
  • 1
    hercules-390

    hercules-390

    Mainframe Emulator - Mirror of http://www.hercules-390.org/

    Hercules is an open source software implementation of the mainframe System/370 and ESA/390 architectures, in addition to the new 64-bit z/Architecture. Hercules runs under Linux, Windows, Solaris, FreeBSD, and Mac OS X. Hercules was created by Roger Bowler and is maintained by Jay Maynard. Jan Jaeger designed and implemented many of the advanced features of Hercules, including dynamic reconfiguration, integrated console, interpretive execution and z/Architecture support. A dedicated crew of programmers is constantly at work implementing new features and fixing bugs.
    Leader badge
    Downloads: 33 This Week
    Last Update:
    See Project
  • Previous
  • You're on page 1
  • Next
MongoDB Logo MongoDB