OpenCOBOL MPE Enhancements

OpenCOBOL, is a freely available open source implementation of the COBOL programming language. Originally designed by Keisuke Nishida, the lead developer is now Roger While. Transformix has adapted OpenCOBOL to serve as a replacement for the HP 3000 COBOL II compiler. It contains HP unique features such as macros.

OpenCOBOL translates COBOL into C and compiles the translated code using the native C compiler. You can build your COBOL programs on various platforms, including Unix/Linux, Mac OS X, and Microsoft Windows.


  • The compiler is licensed under GNU General Public License.
  • The run-time library is licensed under GNU Lesser General Public License.

Project Home

The OpenCOBOL project has its own website at 

Replacing MPE COBOL II

Fortunately for MPE COBOL II users, OpenCOBOL implements enough of the language to be an acceptable substitute when migrating COBOL applications to other platforms. If one’s interest is strictly new development, it contains enough features for application development. However, if one’s goal is to migrate HP 3000 COBOL applications several areas need to be addressed before it becomes a usable solution.

Here is a partial list:

    • Dialect differences
    • COBOL macros
    • KSAM stored copylibs
  • Data access
    • IMAGE
    • KSAM
    • Flat Files
    • MPE Message files
  • Return codes
  • Logic flow
  • Presentation layer
  • Execution of system commands from programs
  • JCL, UDC’s and Command Files
  • Reliance on third party tools such as Suprtool.
  • Batchjobs
  • Spooling

While it is possible to soldier through making all of the above changes required to manually make the changes necessary to make all of this work, it is considerably easier to use Transformix tools to accomplish the same thing.

OpenCOBOL with Transformix Tools

With OpenCOBOL and tools from Transformix, MPE users can be running HP 3000 applications on UNIX, Windows or Linux in record time. The Transformix OpenCOBOL solution includes:

  • A Dialect converter
  • COBOL macro processor
  • Tools to extract Copylibs from KSAM files
  • Data access
    • IMAGE to RDBMS
    • KSAM to RDBMS
    • Flat Files to native files with MPE-like file labels
    • MPE Message files to Message Queuing
  • Return code handling work as it does today
  • Logic flow in your COBOL programs remain the same
  • Presentation layer – VPLUS forms and other MPE-like terminal handling work as they do today or can be upgraded to GUI or Web use
  • Execution of system commands from programs works as it does now
  • JCL, UDC’s and Command Files work with few if any changes
  • Reliance on third party tools such as Suprtool.- most leading tool replacements are available from Transformix
  • Batchjobs work as they do today
  • Spooling works as it does today.

Getting Started

If your goal is strictly to evaluate it without worrying about the difficulties of migrating MPE COBOL II, OpenCOBOL can be installed using one of the many pre-built packages or compiled from sources. If your goal is to run your MPE COBOL programs quickly and relatively inexpensively on UNIX, Windows or Linux contact Transformix