Hey there - one of the Flagsmith founders here - yes we are supporting it, building adapters for our SDKs and I'm on the CNCF project governance board.

We've got the core functionality pretty much down now, and so there's some more interesting/challenging components to think about now like Event Tracking (https://github.com/open-feature/spec/issues/276) and the Remote Evaluation Protocol (https://github.com/open-feature/protocol)

Hey there! Andrew here, Community Manager for OpenFeature and DevRel lead at DevCycle. We (DevCycle) have worked hard to ensure an OpenFeature Provider is available for every language supported by OpenFeature and for which we have an SDK (https://docs.devcycle.com/integrations/openfeature)

Yes there are, as I am part of the openFeature community, I have to point you to https://openfeature.dev/ecosystem where you'll see all kinds of providers which are supported (some officially, some by the community)

LaunchDarkly has a mix of OpenFeature providers they wrote, and quite reasonable community-contributed ones, depending on language. They are also very actively engaged with OF in meetings, discussions, etc.

(We are a big LD user at work.)