I remember there was one more language (besides Simpicity and Bitcoin script) for writing Bitcoin smart contracts. They often referred to it when Solidity came. Can't for the life of me recall the name or even find it anywhere but it was some sort of 3-letter acronym. Does anyone know?
Maybe Miniscript is what you're thinking about?
http://bitcoin.sipa.be/miniscript/Or OTX (Open Transactions)
https://github.com/FellowTraveler/opentxsOr colored coins (that one didn't pan out, IIRC).