By now it’s clear that open source is incredibly powerful – for innovation, user freedom, and building ecosystems. But we also saw why companies may fear going fully open. This is where a new approach to licensing has emerged to balance both worlds: the Business Source License (BSL). We at dotCMS have decided to adopt BSL for our platform, and I want to explain why it makes sense for us (and potentially many other companies).
Read more: Open-source, the future of software, and why dotCMS is now BSL
What is BSL?
In a nutshell, the Business Source License is a “source-available” license that is not an OSI-approved open-source license, but includes a built-in guarantee to become open source later. Think of it as a middle ground between fully proprietary and fully open. Under BSL, we publish our source code for everyone to see, audit, and even modify – so it has the transparency of open source.
All the code is available on our public repo. You can use it freely for development, testing, and certain production scenarios. However, the license imposes some limited restrictions on production use – typically aimed at large-scale commercial deployments or competitors offering the software as a service.
Each BSL project can define what those limits are (often it’s based on revenue, number of users, or specific use cases). The key twist is that this restriction is temporary. The BSL requires that after a set period (for us, it’s four years), the code automatically converts to a fully open-source license (GPL in our case). So, today’s source-available code is tomorrow’s open source. This time-delayed open sourcing ensures that no matter what, the community will eventually have the software under a standard open license. It’s a way of saying: “we, the company, just want a head start to monetize our innovation, but in the long run it will belong to everyone.”
The BSL was originally pioneered by MariaDB Corporation. Back in 2016, MariaDB faced the classic open-source business dilemma with one of their products (MaxScale). They created BSL as a custom license to allow open usage but require a commercial relationship for certain cases, and crucially to guarantee a re-license to GPL. Since then, BSL has been adopted (and adapted) by a number of successful companies navigating the same challenge. It’s been described as a compromise between traditional proprietary licenses and open source, and that’s exactly how we view it.
We love open source, and we want to give as much freedom as possible to our users, while also ensuring we can sustain our business and keep investing in the product for the long haul. BSL gives us that balance.
Importantly, BSL-licensed software is not “closed” – the source is out there and available to the community. In fact, open-source champion Bruce Perens (co-founder of the OSI) has reviewed and endorsed BSL as a legitimate strategy, noting that it still aligns with the spirit of openness since the code does revert to true open source in time. And in our move to BSL at dotCMS, we’ve actually opened up more of our software to the community.
How so? Previously, like many open-core companies, we had a split between a free open-source core aka “community version” and a version with proprietary enterprise features. With BSL, our entire platform’s feature set is now available to everyone to use or trial, regardless of budget, as long as certain criteria are met. Essentially all of our code is out there. We believe this will increase adoption dramatically, because developers and small companies can now access capabilities that used to require an enterprise license.
We truly believe that by moving to BSL, we have actually made dotCMS more open and available for use by a larger audience. Small and mid-sized businesses, hobbyists, nonprofits – they can all use dotCMS without paying a cent under the BSL’s free-use conditions. Only large enterprises deploying dotCMS in production, or third parties offering dotCMS as a service, are asked to purchase a commercial license.