Mainframe Modernization Technology

Mainframe Modernization Technology List

This is a list technologies used for mainframe modernization and replatforming. This list is updated as new information comes in. Feel free to send updates using the contact us and we will update the page promptly.

This information is to assist companies in their research to find the vendors and technologies that best suite their needs; The information should not be relied on as it is accumulated from a variety of sources and self reporting by vendors.

Technology Vendors

  • Advanced

  • Atos

  • AWS


  • DXC

  • EasiRun

  • Ensono

  • GCP

  • GSIs

  • IBM

  • Kyndryl

  • Micro Focus

  • Microsoft

  • mLogica

  • NTT

  • Replatform Technologies

    Replatform Technologies licenses the source code to OpenKicks to companies that want to control their technology stack.

  • TCS

  • Uvsoftware

  • Wipro

  • xFrame


    Micro Focus

    The industry defacto standard as the longest established open systems compiler. Has very good IBM COBOL compatibility when the correct set of compile options are specified. Licensing scheme can vary from case by case so make sure you have licensing costs secured and also make sure licensing will not change after you are in production.

    This compiler generates highly optimized .o or .so files.


    Renamed to GnuCOBOL


    Open Source COBOL that is actively developed with an active community. Renamed from OpenCOBOL after it became part of the Gnu Community. Compiles several dialects of COBOL and the community welcomes bug reports related to IBM COBOL compatibility.

    This COBOL compiler generates C code that is compiled by gcc.


    Open Source COBOL compiler that is only recently inspired. Being developed by small group. This compiler is not yet available but is targeting IBM COBOL compiler compatibility. It will be a first class member of the gnu compiler suite (gcc, gfortran, ggolang, …)

    This compiler generates .o or .so files directly (no intermediate language)


    COBOL-IT is technically an open source compiler because it is a fork of OpenCOBOL but it was commercialized by adding nonopensource components. The commercial implementation was purchased by Micro Focus.

    This COBOL compiler generates C code that is compiled by gcc.

    Recently the original team that forked COBOLIT from OpenCOBOL has created a new company to fork the code from Micro Focus. The new company is called Cloud COBOL.

    Liber COBOL
    P3 COBOL

    This COBOL compiler generates Java code that is compiled by a Java Compiler to Class files. It provides extensions to embed Java directly into COBOL code and to Code COBOL in a Java-Like format named "Java Augmented Syntax". Execution is then in the Java environment of choice.

    This compiler outputs Java which is subsequently compiled to .class files.

    Heirloom COBOL

    Heirloom COBOL is part of their Heirloom Suite for migrating applications from mainframe to JVM. This COBOL compiler was created specifically for migrating mainframe applications to the JVM.

    Heirloom COBOL produces Java which is subsequently compiled to .class files.


    AcuCOBOL is an interpreted COBOL. It was purchased by Micro Focus. It is mostly used by people that are moving an application from one UNIX Platform to another, for instance, Sun to Linux.

    This COBOL compiler generates its own interpreted code that is run by its own runtime.

    Fujitsu COBOL

    This COBOL Compiler is mainly focussed on .NET as a target platform, with different versions for Windows and LINUX.


    IBM COBOL is newly released for Linux and produces compiler messages very similar to Mainframe COBOL.

    One point of possible confusion is that for many years IBM resold the Micro Focus compiler. Some people incorrectly called that the IBM compiler. The IBM COBOL compiler does not share any code with the Micro Focus compiler and is completely distinct.

    This compiler produces .o and .so files directly.

    NTT Enterprise COBOL

    Generates Java class files. Typically used with UniKix and the NTT replatforming tool set.

  • CICS
    NTT TPE formerly UniKix
    Liber Z

    Sold as source to companies that want to control their entire technical stack.

    IBM TX Series
    Enterprise Server (Micro Focus)
  • Assembler

    Converts 370 or 390 Assembler to plain COBOL Code. Subsequent refactoring to well structured COBOL code is possible.

    Liber Iris

    Converts Assembler to COBOL

  • PL1

    Converts PL1 to COBOL

  • JCL
    UV Software

    Batch Processing Engine

  • Liber*Z
  • IMS
  • Scheduler
  • DB2
  • Cloud Providers

    The Amazon mainframe modernization solution is originally the Micro Focus solution with modifications to support cloud based storage.

    Google Cloud Platform
    Oracle Cloud (OCI)
  • Migration Partners

    Every migration is different. These partners will use the set of tools that best matches your requirements.