It's quite more popular than you think. `M-x term` is an example. It's a full-blown terminal emulator in Emacs that runs entirely in another process. Here is an

It's quite more popular than you think. `M-x term` is an example. It's a full-blown terminal emulator in Emacs that runs entirely in another process. Here is another example of async grep/ack/ag: http://tuhdo.github.io/helm-projectile.html#sec-9 http://tuhdo.github.io/helm-projectile.html#sec-9 . As you can see, Emacs gets line by line results from grep/ack/ag without blocking and gives you new results and you type. Or Emacs's fantastic support for communicating with REPLs in many interpreted languages. You can execute any shell command asynchronously while doing other things inside Emacs. You can even compile with beautiful output, in terminal: http://tuhdo.github.io/static/c-ide/compilation-compile.gif http://tuhdo.github.io/static/c-ide/compilation-compile.gif Or built-in GDB integration, also asynchronous: http://tuhdo.github.io/static/c-ide/gdb-many-windows.gif http://tuhdo.github.io/static/c-ide/gdb-many-windows.gif. Another GDB screenshot: https://flic.kr/p/6FW7Q7 https://flic.kr/p/6FW7Q7. And Emacs officially supports asynchronous IO, while in Vim it's a hack from Vim Script.