Escher
Escher is a statically-typed functional programming language that enhances the development of concurrent and distributed systems by providing built-in mechanisms for message-passing concurrency and fault tolerance. Its main uses include creating scalable and reliable applications in domains such as distributed systems, cloud computing, and event-driven architectures.
Popularity: Less than 1% of developers are using or have used this language.*
*According to StackOverflow's 2023 survey.