Mainframe Package Bureau.
Welcome!
The mainframe community has been sharing code longer than most programming communities have existed. The CBT Tape has been circulating since 1975, back when sharing software meant Arnold Casinghino physically mailing magnetic tapes to people who needed them. Before GitHub, before SourceForge, before the phrase "open source" was even coined, mainframe programmers were distributing assembler macros, ISPF dialogs, and COBOL copybooks to each other on reels of tape through the postal service. That is the tradition this project stands on.
MPB is a package manager for mainframe languages. COBOL, HLASM, REXX, PL/I, JCL, and Fortran. You type mpb install and it fetches the code from wherever the author keeps it. That's the whole idea. No ceremony, no accounts, no cloud dashboards. Just code arriving where you need it, which is more or less what Arnold was doing fifty years ago except now the tapes are git repositories and the postage is free.
We would like to thank everyone who has contributed packages and tools over the years. Lionel Dyck, whose decades of ISPF and REXX tooling have quietly made life better for mainframe developers everywhere. Don Higgins, who created z390 and proved that a portable mainframe assembler could exist outside of IBM hardware. Abe Kornelis, who has kept z390 alive and thriving as a community project with tireless dedication. And Arnold Casinghino, who started the CBT Tape in 1975 and built the culture of sharing that all of this rests on.
If you have something useful sitting on your system that other people might benefit from, we would genuinely love to hear from you.
Download mpb.exe from the latest release, then:
mpb search
mpb install cobol-dateutilThe copybooks are now in mpb_packages/cobol-dateutil/src/ and you can COPY them into your program.
mpb install <pkg> install a package from the registry
mpb remove <pkg> uninstall a package
mpb update <pkg> pull the latest version
mpb search <query> search packages by name or description
mpb search list everything in the registry
mpb info <pkg> show package details, license, and repo
mpb list show what you have installed locally
mpb init <name> <lang> create a package.json for a new package
$ mpb install cobol-dateutil
mpb: cobol-dateutil v0.1.0 (cobol) by Zane Hambly
mpb: Date arithmetic for COBOL. Business days, day count conventions, ISO weeks.
mpb: license: Apache-2.0 — permissive (safe for commercial use)
mpb: cloning from https://github.com/Zaneham/cobol-dateutil
mpb: installed cobol-dateutil v0.1.0
For copyleft packages it will let you know before proceeding, because introducing a GPL dependency into a proprietary codebase is the sort of thing that goes better when it involves a conversation with someone in legal rather than a surprise six months later:
$ mpb install zigi
mpb: zigi v4.0.0 (rexx) by Lionel B. Dyck
mpb: The git interface for the rest of us. ISPF dialog for z/OS git operations.
mpb: license: GPL-2.0 — COPYLEFT (derivative works must be open source)
mpb: proceed? [y/N]
$ mpb search
zblas 1.0.0 [hlasm] Apache-2.0 z/OS native BLAS with z13+ vector SIMD
cobol-dateutil 0.1.0 [cobol] Apache-2.0 Date arithmetic, business days, day count conventions
cobol-ebcdic 0.1.0 [cobol] Apache-2.0 EBCDIC/ASCII conversion, CP037 and CP500
zigi 4.0.0 [rexx ] GPL-2.0 The git interface for the rest of us
CBTView 1.0.0 [rexx ] GPL-2.0 Access to the CBTTape from ISPF
racfadm 1.0.0 [rexx ] GPL-2.0 RACF administration and reporting
pdsegen 1.0.0 [rexx ] GPL-2.0 PDSE Version 2 member generation
xmitip 1.0.0 [rexx ] GPL-2.0 z/OS email client
ftpb 1.0.0 [rexx ] GPL-2.0 FTP from ISPF
whoson 1.0.0 [rexx ] GPL-2.0 TSO users across the sysplex
omvscmds 1.0.0 [rexx ] GPL-2.0 OMVS shell commands from ISPF
algol-stringlib 0.1.0 [algol] Apache-2.0 String handling for Burroughs Extended ALGOL
rpg-dateutil 1.1.0 [rpg ] Apache-2.0 Date utilities, business days, NZ holidays
Ten languages, and growing. If you have something to share we would love to have it.
Every package carries an SPDX license identifier. MPB classifies them before installation so there are no surprises:
| Classification | Licenses | What happens |
|---|---|---|
| Permissive | Apache-2.0, MIT, BSD, ISC | Installs with a note |
| Weak copyleft | LGPL, MPL-2.0, EPL-2.0 | Installs with a note |
| Copyleft | GPL-2.0, GPL-3.0, AGPL-3.0 | Warns and asks for confirmation |
| Proprietary | PROPRIETARY, UNLICENSED | Warns and asks for confirmation |
| Unknown | Missing or unrecognised | Warns and asks for confirmation |
This is not legal advice and never will be. It is a friendly tap on the shoulder before you do something that might require a less friendly conversation later.
The registry lives in its own repository at mpb-registry. It contains an index.json and one small package.json per package. Each package.json points to the author's own repository where the actual code lives.
Nobody uploads their code to the registry. The registry is an index, not a warehouse. Your code stays in your repo, under your control, with your license. MPB just tells people where to find it.
A package entry looks like this:
{
"name": "cobol-dateutil",
"version": "0.1.0",
"description": "Date arithmetic for COBOL.",
"author": "Zane Hambly",
"license": "Apache-2.0",
"language": "cobol",
"repository": "https://github.com/Zaneham/cobol-dateutil"
}Fork mpb-registry, add a directory under packages/ with your package.json, update index.json, and submit a pull request. Same model as Homebrew and the Notepad++ plugin list. If pull requests aren't your thing, open an issue with a link to your repo and we will sort it out.
| Code | Language | Typical Files |
|---|---|---|
| cobol | COBOL | .cpy, .cob, .cbl |
| hlasm | HLASM | .asm, .mac |
| rexx | REXX | .rexx, .exec |
| pli | PL/I | .pli |
| jcl | JCL | .jcl |
| fortran | Fortran | .f, .f77, .f90 |
| algol | ALGOL | .alg |
| newp | NEWP | .newp |
| wfl | WFL | .wfl |
| rpg | RPG | .rpgle, .sqlrpgle |
ALGOL, NEWP, and WFL are for the Unisys (Burroughs) folks. Yes, we know you're out there. Yes, we remembered you. You're welcome.
If your favourite mainframe language still isn't here, let us know. The architecture supports adding new ones with a single line of code.
Pre-built binary (easiest): Download mpb.exe from the latest release and put it somewhere in your PATH.
Build from source:
makeEither way, you need curl and git on your system. MPB uses curl to fetch package metadata and git to clone repositories.
Contributions are welcome and genuinely appreciated, whether that's a new package for the registry, a bug fix in the CLI, or just a note saying you tried it and something didn't work. The mainframe community has always been generous with its knowledge and we would like MPB to reflect that.
If you are one of the people who has been quietly maintaining REXX execs and COBOL copybooks and HLASM macros for years without much recognition, thank you. Seriously. This project exists because of the work you've already done.
Apache 2.0.