Junction
Junction is a datapack programming language, mainly designed, like all datapack languages (I hope), to reduce the headache of writing datapacks by hand, as well as to try and shield breakage between versions, which I'm not sure I've seen anyone else do.
I think this is an interesting endeavor, as datapacks break between versions of Minecraft, though I don't really write datapacks anymore, so I'll leave this to someone else.
This also got me thinking about language platforms really, which I might write about some day in the future.