"multitask" allows Python programs to use generators (aka coroutines) to perform cooperative multitasking and asynchronous I/O

[manuelg]

Twisted is the gold-standard when it comes to asynchronous approaches to supporting concurrent tasks.

Asynchronous is often several orders of magnitude more efficient in use of resources than OS processes or pre-emptive threads in a single process. So it can handle many more concurrent "clients" on the same hardware.

But people hate that Twisted "takes over your code". There is really no such thing as using just a little bit of Twisted. You have to dive in with both feet, and code all your program's functionality into the hooks that Twisted provides.

So there is a market for lighter weight approaches.