The O'Saasy License and the Definition of Open Source

In early September, David Heinemeier Hansson (DHH) announced that his latest project, the kanban tool Fizzy, would be released under the O'Saasy license. The license explicitly prevents competitors from offering a SaaS version of the software, a restriction that critics argue violates the Open Source Initiative’s (OSI) definition of open source.

“Open source is when the source is open. Simple as that.” – DHH, X

The statement was met with swift rebuttal from WordPress founder Matt Mullenweg, who compared the claim to a country calling itself a democracy. While the analogy was clumsy, the point was clear: the term “open source” has a shared, historically‑shaped meaning that cannot be repurposed for marketing.

“You can’t ignore the Open Source Initiative definition. It’s not a loose idea.” – Mullenweg, X

Why the Debate Matters

The argument is more than semantics. The open‑source community relies on a common vocabulary to coordinate contributions, licensing, and governance. When influential figures redefine that vocabulary, it can erode trust and create confusion about what projects can legally do.

At the same time, the debate surfaces a persistent tension: many companies monetize open‑source software while leaving the heavy lifting of development to volunteers. DHH’s choice of the O'Saasy license is an experiment aimed at balancing commercial interests with community benefits.

“The definition debate matters because open source only works when we agree on what the term means.” – Dries Buytaert, Source Available Is Not Open Source, And That Is Okay

Sustainability vs. Definition

While the definition debate is essential, the real challenge lies in sustainability. Projects like Drupal, WordPress, and Ruby on Rails have endured for decades, partly because large companies contribute back to the ecosystem. Yet the imbalance persists, and the community continues to wrestle with free‑riding.

Buytaert notes that WordPress has been under the GPL for over twenty years, making a license change practically impossible. In contrast, Fizzy’s new license allows DHH to experiment with different models.

“If the definition is just 'shit people made up', what spirit was Matt violating?” – DHH, X

Experiments and Questions

Buytaert highlights ongoing experiments in Drupal, such as contribution credits and guiding corporate work toward the project. These initiatives illustrate attempts to address the imbalance, though they have not fully solved the problem.

He concludes with a set of questions that could steer the conversation away from word games toward actionable solutions:

  1. How do we distinguish between companies that can’t contribute and those that won’t?
  2. What actually changes corporate behavior: shame, self‑interest, punitive action, exclusive benefits, or regulation?

“If this latest fight nudges us away from word games and toward these questions, some good may come from it.” – Dries Buytaert

Bottom Line

The clash between DHH and Mullenweg underscores a broader reality: open‑source sustainability is not a single‑sentence definition but a complex ecosystem of licensing, community norms, and corporate responsibility. As the debate continues, the community must decide how to balance commercial viability with the shared values that keep projects alive.

Source: Dries Buytaert, “Source Available Is Not Open Source, And That Is Okay” – https://dri.es/source-available-is-not-open-source-and-that-is-okay