I just wanted to shout out TRMNL.

They have an interesting product, and they're trying to build a business that includes a lot of open source aspects.

The device that they sell is proprietary, but it's also just an ESP32, screen, enclosure, and battery, with a custom PCB for convenience. They plan to add instructions to build your own device, and their firmware is open source under a GPLv3 license.

By default, their device connects to their servers, and they have a slick web configuration tool for people who don't care about having smart devices call home, but you can easily modify the firmware to connect to your own self-hosted server instead. As of this evening, both the Phoenix and Sinatra server implementations are open source under an MIT license after I pointed out that they had no license in an issue, and they pretty much immediately updated the repositories.

There are two other repositories that they have not added a license to, but given their swift response, I'll give them the benefit of the doubt, and I would expect them to be updated shortly.

They have not shared all of the plugins that are available on their hosted service for use on a self-hosted instance, but a few are available for use and there are many plugins made by others available as well!

As soon as they update those last two repositories, I plan to pre-order one (unlike the conceptually cool VU Dials who's creators still have not added a license even after being called out by the co-creator of Rocky Linux).