It turns out I had quite a collection of e-paper screens and wanted a simple way to drive them all. Something flexible, customizable, and that didn't require a cloud account. I couldn't find anything that fit my needs exactly, so I decided to roll my own solution.
What I ended up with: an HTML-based widget system that gets captured headlessly via Playwright, gets dithered and composed via panel-specific renderers, and then published to clients via REST or MQTT. All components (Widgets, renderers, and device kinds) are drop-a-folder plugins.
Hardware supported: Pimoroni Inky Impression panels via a client daemon, Waveshare panels via custom firmware, Seeed reTerminal and TRMNL devices via TRMNL firmware as well as jailbroken Kindles (or anything that has a TRMNL client)
The server publishes dashboards to all of these via a built-in rotation system.
The server and clients are AGPL-3.0-or-later. There are install scripts for windows/linux/OSX as well as full Home Assistant App support, Docker containers, or cloud-init.
This is my first post here. I hope people find this useful.