Open Source Software for Music Publishers

When it comes to open-source solutions for music publishers, there are very few practical ones. But before we go into details, we must ask the big question: “Why open source?”

Why Open Source?

Because it is free? Well, free software is not free lunch (there is no such thing, BTW). Let’s take it from Free Software Foundation:

Free software is software that gives you the user the freedom to share, study and modify it. We call this free software because the user is free. To use free software is to make a political and ethical choice asserting the right to learn, and share what we learn with others.

Because the user is free. But this political and ethical choice often has a higher financial cost than the cheapest closed source alternative, and for early adopters, the open source solution might even be the most expensive one. The reasons for open source should not be sought in cost reduction. I do not believe in financially unsustainable political or ethical choices, so for me, it only makes sense if using it will increase revenues compared to using closed-source solutions.

Current Open Source Solutions

Let’s have a look at what is currently out there.


WESO - Web Semantics Oviedo has published several open-source repositories related to CWR. I tested the parser a while back and it worked well. However, creating CWR was not covered at the time, and as far as I can tell, it is still not.

WESO has shown little activity in the past few years. Besides the core CWR project, they started several other related projects which seem abandoned. Still, an open-source can easily be forked and revived. But when it comes to music publishers who want to create CWR files, it has very little value.


An excellent basic PHP library for reading, writing and manipulating CWR files. It has been used in production for years by Aporia. It will convert CWR-compliant data to CWR, but if data is not CWR compliant, resulting CWR may not be valid either, as the validation is incomplete.

APORIA is actively developed and may be a great add-on for in-house projects, particularly those written in PHP. However, there are no plans for it to become anything more than just the generation/parsing library.

Django Music Publisher

Django Music Publisher is open-source software for original music publishers. It is a tool for managing metadata for musical works and recordings, including data about writers, recording and performing artists, albums and music libraries, as well as royalty distribution processing. By me.

Music Metadata - Python libraries

This is a series of libraries for music metadata management, released as open-source. Still in the early stage, they are to replace most of the tools on this web site. Also by me.