As an EVM, contracts on Ubiq are written in Solidity.
"Solidity is an object-oriented, high-level language for implementing smart contracts. Smart contracts are programs which govern the behaviour of accounts within the Ethereum state."
If you are coder looking to deploy contracts on the Ubiq network, becoming familiar with Solidity is a must. Inherited from the wider Ethereum environment, Solidity is the basis on which all contract code is created for Ubiq.
You can learn about about Solidity from their official documentation HERE.
If you are just starting out and looking for a Solidity resource that is approachable for beginner's level understanding, you may find the CryptoZombies course by Loom to be a good place to start.