Marlowe is a new language for modeling financial instruments as smart contracts on a blockchain. It has been designed for people who are business engineers or subject experts rather than experienced developers. It is a simple domain-specific language (DSL) which comprises a small number of powerful building blocks that can be assembled into expressive financial contracts. It is embedded in the Haskell language, which has its own established ecosystem and testing framework. You do not need programming expertise to use Marlowe and you can explore your Marlowe financial constructions with a browser-based contract editor and simulator.