Category: Uncategorized

Source-available software licenses have become increasingly popular in recent years. They share properties with both open source and proprietary licenses, and often are confused with each.

Source-available as a category has been around for quite a while, but it made a big splash with the announcement of the Commons Clause in 2018 in a TechCrunch article called Commons Clause stops open-source abuse.

That blog post was intentionally provocative, spurring a discussion of “strip-mining” or “cloning” of SaaS that was allowed under open source licenses. The ability of cloud users to avoid source code sharing was an issue that had already been acknowledged by open source advocates, and had eventually resulted in the publication of the Affero GPL. Even copyleft licenses like GPL do not require source code sharing in back-end SaaS deployment. But the “strip-mining” camp went further, saying that even network copyleft licenses like AGPL only extend to a single program and therefore did not require sharing of essential monitoring, hosting, and management software–all of which are key to cloud deployment. Businesses that were developing around the open core model–as well as their investors–were frustrated about what they viewed as free-riding and refusal to share with the open source community. Although that frustration was often directed at Amazon.com, the ability to clone and sell software applied equally to all of the cloud providers.

Commons Clause Was not the First, Just the Loudest

But in fact, there were already at least a couple of notable examples of source-available licenses that pre-dated the bombshell of Commons Clause: SourceGraph’s Fair Source License and MariaDB’s Business Source License.

After the Commons Clause blog, open source advocates began what they viewed as a battle for the hearts and minds of the software world, claiming, among other things, that source-available would destroy open source and calling it a “license to kill.” The source-available was more practical and less doctrinaire, and sought to re-examine what freedoms their communities cared about the most. They posited that source code availability, and the transparency it engendered, was more important than an completely unrestricted license. Many of them were long-time open source developers.

Of course, source-available hasn’t killed open source. Far from it: if anything, it has emerged as a complementary licensing model that promotes open source. That’s because of one key aspect that open source advocates ignored in their race to condemn it. Source-available is a substitute for binary-only proprietary licenses, not open source licenses.

Many businesses today offer their products under a mix of licenses, each one offering set of rights that is intended to work for the community and for customers, as well as the vendor. Often, some is often open source, some source-available, some closed source, and some SaaS (which requires no license terms at all). Savvy businesses today use licensing models that are designed to offer all the rights they can in each category.

What is Source-Available?

At a high level, source-available licenses have three attributes:

1. They make source code available 
2. They impose at least one license restriction 
3. They’re implemented in a frictionless manner

Source-available licenses are deployed like open-source licenses — and people have a tendency to mistakenly refer to source-available as open source — but they’re not the same. This is because source-available licenses put restrictions on the use of the software, while true open-source licenses do not. 

Frictionless here means there is no click-to-accept process. Source-available uses the same premise as open source: you may not have accepted the license, but if you haven’t, you have no rights. So the user has no interest in making that argument, which is referred to in law as a formation argument–that the terms were never accepted and therefore the contract was never formed.

Source-Available is Growing Up

This website and blog is dedicated to explaining and recognizing source-available as its own category. The failure to do that in the past has contributed to the confusion between open source and source-available. But confusion doesn’t help advocates of either category.

Source-available is tremendously popular in tech businesses, and well received by most users. It’s time to stop the “us versus them” approach, and make room for this category, instead of pretending one of these categories must “destroy” the other. In reality, there is a place for each, and their co-existence is already quite common. We need clarity, not rhetoric.