One of these things is not like the others

The Commons Clause vs. Open Source controversy, explained

Jane Elizabeth
© Shutterstock / charles taylor

Do you know what’s in your open source license? Turns out, if you’ve got the Commons Clause in there, it might not be as “open” as you think. We take a look at the Commons Clause and explore how it is different from your average open source license.

The open source wars are heating up again. Although you might not see a big difference between one license and another, making the wrong choice can have serious financial and legal consequences. The latest license, the Commons Clause, is poised to set off a new round of legal fights in the open source community.

Last month, Redis Labs made headlines when they attached the Commons Clause to their open source in-memory data structure store, Redis. Redis is primarily used as a database, cache, and message broker and it’s a wildly popular part of the modern internet’s infrastructure. A change to their license is a big deal.

So, what is Commons Clause and why isn’t it the same thing as open source?

New kid on the block

It’s not unusual for a new open source license to come along. Technology changes and we decide new approaches are better. (Or, the lawyers get involved and tell us we definitely need to change that one clause, right now.)

The Commons Clause is most definitely not an open source license. They are very, very clear about this.

Instead, it’s a license condition that runs on top of an existing open source license to narrowly restrict it for commercial use. When applied to a project, existing users are not immediately affected. Previous licenses aren’t revoked; it just applies to code going forward.

The Commons Clause license forbids developers or enterprises from selling the software. It also explicitly forbids hosting, consulting, or supporting services as “a product or service whose value derives, entirely or substantially, from the functionality of the software”.

In essence, the Commons Clause was designed to stop enterprises from profiting off of open source work. If a major corporation takes advantage of the free nature of an open source project without financially supporting it, there’s nothing to stop them from not giving back to the community.

Big tech companies love to talk about using open source, but do they financially support those projects? Not always. So the Commons Clause was designed to force a negotiation with these companies while still maintaining some of the values of the open source community.

With the Commons Clause, developers can hopefully benefit from commercial use of their work. After all, just because you have a wildly successful open source program, that doesn’t mean you’ll be able to monetize it successfully.

SEE ALSO: Is Commons Clause open source? Weighing in on the Redis license change

The 10 open source commandments

However, the narrow changes that make up the Commons Clause also make it not open source.

Simon Phipps, the president of the Open Source Initative, characterized the Commons Clause as “an abrogation of software freedom.”

The main definition for open source comes from the Open Source Initiative (OSI). A venerable institution, this non-profit has been regulating what open source is for over 20 years. In addition to making the original source code open access, the program has to follow a laundry list of criteria, including:

  1. Free redistribution with no royalties
  2. Source code has to be easily distributed
  3. Modifications and derivations are allowed
  4. The author’s source code can remain intact if specified
  5. No discrimination against any person or group
  6. No discrimination against specific fields or endeavors
  7. Distribution of license applies to anyone who uses the program
  8. The license is not program-specific
  9. The license cannot restrict other programs
  10. The license must be technology neutral

Intrinsically, the open source community believes that software must be free. It doesn’t take much to see the big difference between the Commons Clause and the OSI.

SEE ALSO: Open source: The next 20 years

So, why go Commons Clause?


The tragedy of the commons is a big problem in open source developing. Developing is hard work and no one particularly enjoys it when their clever technological invention isn’t financially rewarded.

However, that doesn’t mean using the Commons Clause will rake in the cash. The Commons Clause license forbids selling “a product or service whose value derives, entirely or substantially, from the functionality of the Software.” But what does substantially mean? This could be a major point of contention in any lawsuit.

The Commons Clause is also a major blow to the OSI’s hegemony in maintaining the licensing field. Some are concerned about this starting another round of fragmentation amongst the open source community, as companies and developers offer their own individualized licensing.

As of right now, though, it’s too early to tell how this will all work out. But someone ought to tell the major tech companies that they might have a bill coming soon.

Jane Elizabeth
Jane Elizabeth is an assistant editor for

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