To be fair, they admit it isn't usable for "real" software: About Mars ... Mars is an experiment, not a full-featured programming language. You can use

To be fair, they admit it isn't usable for "real" software: About Mars ... Mars is an experiment, not a full-featured programming language. You can use it for playing with the boundaries between imperative and declarative programming, but we don't recommend you write real software with it.