SlackBuildsOrg/libraries/greenlet

The greenlet package is a spin-off of Stackless, a version of CPython
that supports micro-threads called "tasklets". Tasklets run
pseudo-concurrently (typically in a single or a few OS-level threads)
and are synchronized with data exchanges on "channels".

Greenlets are provided as a C extension module for the regular
unmodified Python interpreter.

Greenlets are lightweight coroutines for in-process concurrent
programming.