Async is a library for asynchronous programming, i.e., programming where some
part of the program must wait for things that happen at times determined by some
external entity (like a human or another program). This includes pretty much any
program that uses blocking calls (e.g., networking code, disk access), timeouts,
or event loops (e.g., GUIs).

Homepage:
https://github.com/janestreet/async/
