OVOS is a community based continuation of mycroft-core, we formed essentially as a distro even before mycroft fully collapsed
Neon AI also predates Mycroft’s collapse, Neon is a commercial company and took over support for the Mark2 and these forums, but they have their own codebase built on top of OVOS (think of OVOS as a library in this case)
when Mycroft collapsed we wrote a FAQ, and i see @NeonClary has continued to edit it so it should be up to date
we also have a detailed timeline of events for everything Mycroft/OVOS, if you want to dig deep into our history that shows how OVOS was born
We have been continuously improving the (python side) gui framework, the original QT gui has been forked under OVOS and is under life support, we only have basic experience with QT and no time to fully maintain the project, but the original author was one of the founders of OVOS and did a bunch of work before leaving, including the ovos-shell used in the Mark2 images (from OVOS and Neon). He also started migration to QT6 but left before finishing that.
As for attribution, the individual repositories as far as we know all comply with the license and are properly attributed as forks, as well has having the appropriate license headers. We also list BlueSystems (who sponsored the lead mycroft-gui developer) in our friends page and prominently mention QT in our docs, PRs welcome if something is unclear
@mikejgray summed up the situation quite well, we want to support the GUI and will give all the help we can, but we need some QT developers to help. The OVOS Foundation never had any official contact with KDE, we would be happy to have a chat and coordinate with others if there is interest and possibility of onboarding some developers!