In my experience, amateur radio (both licensed and license-free) and 3d printing both seem to have cultural perspectives on open source that differ considerably from the regular open source software community.

But while in 3d printing, outside of hardware, that difference often feels confused (eg, I've seen the Multiboard creator post compliments online about models that blatantly violate his own license), in radio the difference often feels hostile. You have OpenGD77, for example, with its 'we were never GPL' rug-pull that was likely illegal (they had outside contributions) [1]. You have Meshcore with its 'we are open source, except...', and, as you can see in this thread, a difficulty actually finding parts of the code. You have the heavy cultural push against uSDX (seemingly open hardware+source) toward truSDX (DRM-encumbered), and what seems like the quiet acceptance of things like QMX, where you can solder together a radio with DRM that prevents you from installing your own firmware. You even have digital modes that are legally required to be publicly documented, and actually aren't in any meaningful way: VARA FM is probably the worst offender [2], but even modes that are in-crowd enough to be advertised in FCC license exam questions are often effectively proprietary and legally dubious.

What's particularly foreign to me about the culture is that oftentimes, much of the community seems to support behavior that seems malicious from an open source perspective, and attack the open source proponents.

[1]: https://hackmd.io/@ajorg/opengd77-is-closed [2]: https://themodernham.com/reverse-engineering-vara-fm-part-1-...