I plan to release the first alpha build of Feathers UI for Haxe/OpenFL by the end of February. Much of the core architecture is solid, but only a subset of components have been ported over.
I am currently focused on writing documentation for this alpha build. I don't expect to make many code changes between now and the alpha, so the current state of the source code on Github now is probably not much different from what's going to be released in the next month.
See https://api.feathersui.com/unstable/ for the list of what classes/components are available currently. This API reference is automatically updated with every push to Github.
See https://github.com/BowlerHatLLC/feathersui-openfl/issues/6 for some compatibility/migration tables that track the current progress at a relatively high level.
The user manual is here (but is not yet fully complete for the alpha): https://feathersui.com/learn/haxe-openfl/