Escher isn't the most practical new programming language, but it is nothing if not interesting. From the language in the README, I honestly couldn't tell if it was sincere at first. Then I got to the bibliography and decided that Escher's author is definitely not joking.
A few choice quotes:
Escher is a language for building intelligent real-time translations between the semantics of different physical devices accessible through chains or networks of digital or electrical technologies.
From the point-of-view of an Escher program, there is no input and output: There are only emergences and disappearances of events.
An Escher program is a collection of interconnected reflexes. A reflex, the only abstraction in Escher, represents an independent computing entity that can interact with the “outside world” through a collection of named valves.
I doubt you'll want to build your next big app with Escher, but it scores point for mind expansion and having a great name. If nothing else, spend 15 minutes reading through some of its ideas.