Python and Python Wheels for OpenVMS

Thank you for your interest in this port of Python for OpenVMS x86-64. This release of Python for OpenVMS is based on the Python 3.10.0 Open Source distribution and is the first full release of Python for OpenVMS x86-64. Note that other than Python proper, this release also includes a dedicated Python packages kit (for details, see Section 4, ''Installing the Kits'').

Python (https://www.python.org/) is an interpreted high-level programming language for general-purpose programming that emphasizes code readability. It provides constructs that enable clear programming of both small- and large-scale software applications. Python features a dynamic type system and automatic memory management. The Python language supports multiple programming paradigms, including object-oriented, functional, and procedural, and has a large and comprehensive runtime library.

This OpenVMS port of Python comprises two kits, namely a core Python kit and a Python packages kit. The core Python kit includes the core binary Python distribution and various OpenVMS-specific extensions, including interfaces for OpenVMS products, along with interfaces for many OpenVMS system services and library calls. The packages kit includes a substantial collection of commonly used Python packages, including modules for web application development, integration, and testing. It is anticipated that additional packages will be included in future releases. It is also possible for users to readily download and install many other Python packages directly from the Python Package Index repository at https://pypi.org/ or elsewhere using the Python PIP package installer.

The kit you are receiving has been compiled and built using the operating system and compiler versions listed below. While it is highly likely that you will have no problems installing and using the kit on systems running higher versions of the products listed, we cannot say for sure that you will be so lucky if your system is running older versions.

In addition to the above requirements, it is assumed that the reader has a good knowledge of OpenVMS and of software development in the OpenVMS environment.

It is recommended that software developers read some of the excellent tutorials and other documentation available via the Python web site (https://www.python.org/). The web site provides numerous links to books, technical guides, tutorials, and many other documents that provide useful information on developing applications using Python.

In addition, the VSI wiki provides the following pages, which provide details regarding many of the OpenVMS-specific modules, and details of compatibility issues that may be relevant to developing and using Python applications on VSI OpenVMS.

It should be noted that the documentation for OpenVMS-specific modules is at this time incomplete. It is anticipated that this documentation will be updated over the coming months to include details for all such modules.

The core Python kit also includes a number of simple example and test programs in the directory PYTHON$ROOT:[LIB.PYTHON^.10.TEST] that serve to illustrate the usage of some of some of the OpenVMS specific extensions. It is envisaged that additional examples will be added over time.

As noted previously, this OpenVMS port of Python comprises two compressed PCSI kits, namely a core Python kit and a packages kit (also referred to as the “wheels” kit).

Note that the packages kit is based on Python wheels (see https://pythonwheels.com/), which provides a flexible and efficient means of installing optional Python packages. While it would be possible to combine the core and packages kits into a single installable kit, it is unlikely that all packages in the packages kit will be of interest to all users. It is also envisaged that the list of packages and package versions will be updated more regularly than the core distribution.

$ PRODUCT INSTALL PYTHON

The following product has been selected:
    VSI X86VMS PYTHON V3.10-10             Layered Product

Do you want to continue? [YES]

Configuration phase starting ...

You will be asked to choose options, if any, for each selected product 
and for any products that may be installed to satisfy software dependency requirements.

Configuring VSI X86VMS PYTHON V3.10-10: Python for OpenVMS is based on Python Version 3.10

    (C) Copyright 2025 VMS Software Inc.

    VMS Software Inc.

* This product does not have any configuration options.

Execution phase starting ...

The following product will be installed to destination:
    VSI X86VMS PYTHON V3.10-10             DISK$X86SYS:[VMS$COMMON.]

Portion done: 0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100%

The following product has been installed:
    VSI X86VMS PYTHON V3.10-10             Layered Product

VSI X86VMS PYTHON V3.10-10: Python for OpenVMS is based on Python Version 3.10

    Post-installation tasks are required.

    To define the Python runtime at system boot time, add the
    following lines to SYS$MANAGER:SYSTARTUP_VMS.COM:

        $ file := SYS$STARTUP:PYTHON$STARTUP.COM
        $ if f$search("''file'") .nes. "" then @'file'

$ set process/parse_style=extended
$ python :== $python$root:[bin]python.exe
$ set default python$root:[lib.python3^.10]
$ python compileall.py ./

$ PYTHON :== $PYTHON$ROOT:[BIN]PYTHON.EXE

$ PRODUCT INSTALL PYTHWHLS

The following product has been selected:
    VSI X86VMS PYTHWHLS V1.1-7             Layered Product

Do you want to continue? [YES]

Configuration phase starting ...

You will be asked to choose options, if any, for each selected product 
and for any products that may be installed to satisfy software dependency requirements.

Сonfiguring VSI X86VMS PYTHWHLS V1.1-7: Python wheels collection for OpenVMS Python 3.10

    (C) Copyright 2026 VMS Software Inc.

    VMS Software Inc.

* This product does not have any configuration options.

Execution phase starting ...

The following product will be installed to destination:
    VSI X86VMS PYTHWHLS V1.1-7             DISK$X86SYS:[VMS$COMMON.]

Portion done: 0%...10%...20%...50%...60%...80%...90%...100%

The following product has been installed:
    VSI X86VMS PYTHWHLS V1.1-7             Layered Product

VSI X86VMS PYTHWHLS V1.1-7: Python wheels collection for OpenVMS Python 3.10

    Post-installation tasks are required.

    To define the Wheels for Python runtime at system boot time, add 
    The following lines to SYS$MANAGER:SYSTARTUP_VMS.COM:

        $ file := sys$startup:python_wheels$startup.com
        $ if f$search("''file'") .nes. "" then @'file'

$ python -m pip install --no-index module-name

$ define PIP_NO_INDEX 1

As noted previously, this OpenVMS port of Python comprises a core Python kit and a Python packages kit.

The core Python kit includes the core binary distribution and various OpenVMS-specific extensions, including interfaces for OpenVMS products, along with various facility definitions (item codes and error codes) and interfaces for many OpenVMS system services and library calls. The following table summarizes the OpenVMS-specific packages:

Several simple example and test programs for some of these extensions can be found in PYTHON$ROOT:[LIB.PYTHON^.10.TEST], and several examples for the OpenVMS RMS extension can also be found in PYTHON$ROOT:[LIB.PYTHON^.10.VMS].

Note that the core distribution also includes the following two default packages:

The PYTHWHLS packages kit includes a collection of commonly used Python packages, including packages for web application development, integration, and testing. The following table lists the various packages that are included in this release of the PYTHWHLS kit. It is envisaged that this list will be periodically updated to include additional packages as well as new versions of existing packages. Details about each of these packages may be found at https://pypi.org/.

Note that if a particular package is not currently included in the PYTHWHLS kit and your OpenVMS system is able to access the internet, in most cases it will be possible to download and install the desired package directly using the python -m pip install <module-name> command.

Future releases of Python for OpenVMS may include a more comprehensive suite of such modules along with accompanying documentation and example programs.

Developers can implement their own dynamic Python modules (shareable images) by including in their projects the Python header files found in PYTHON$ROOT:[INCLUDE] and by linking with the shareable image PYTHON$ROOT:[LIB]PYTHON$SHR.EXE. Note that the logical name PYTHON$SHR is defined by the Python start-up procedure and may be used to link with the shareable image. Symbols in the shareable image are mixed-case, and developers should use the C compiler option /NAMES=(AS_IS,SHORTENED) or include in their code appropriate #pragma directives to ensure that symbols are correctly resolved when linking.

$ python /sys$login/local/bin/s3cmd <command>