There's also the "open-core model"[^1]. From the Wikipedia description:

>The open-core model is a business model for the monetization of commercially produced open-source software. Coined by Andrew Lampitt in 2008,[1] the open-core model primarily involves offering a "core" or feature-limited version of a software product as free and open-source software, while offering "commercial" versions or add-ons as proprietary software.[2][3]

Here's GitLab's CEO[^2] talking about "Offering an on-prem / self-managed version of your software"[^3]

Here's a timestamped video titled "E05 Pioneering version control for data science with Pachyderm co-founder and CEO Joe Doliner"[^4], where Pachyderm's CEO[^5] addresses the business model.

Here's a timestamped video, titled "How to Find Product Market Fit", of Peter Reinhardt[^6], where he answers the question of "why would someone pay anything for an open source library that's 580 lines of code.."[^7]. There's a blog post detailing this, too[^8].

There are several degrees of what is open-source and what is not, and different ways to build a business around that.

[^1]: https://en.wikipedia.org/wiki/Open-core_model

[^2]: https://news.ycombinator.com/user?id=sytse

[^3]: https://www.youtube.com/watch?v=Lo0bejtOnQc

[^4]: https://youtu.be/YG8VFOZBb2A?t=1288

[^5]: https://news.ycombinator.com/user?id=jdoliner

[^6]: https://news.ycombinator.com/user?id=pkrein

[^7]: https://youtu.be/_6pl5GG8RQ4?t=1871

[^8]: https://segment.com/blog/show-hn-to-series-d/