I have been looking all day for a FOSS keyboard that's under active development. It seems like more of not all of the ones I've seen recommended haven't been updated in over a year some three years. I don't mind if it's a long time between updates but I want to know bugs will be fixed eventually.
FlorisBoard is great! It's not had a release in about year but that doesn't mean it's not under active development. The developer is currently working on the Natural Language Processing component.