Eventlet vs Greenlet vs gevent?

I'm trying to create a GUI framework that will have an event-loop. some threads to handle the UI and some for event handling. I've searched a little bit and found these three libraries and I'm wondering which one is better to use? what are the pros and cons?

I could use one of these three library or even create something for myself by using python threads, or concurrent library.

I would appreciate sharing any kind of experience, benchmark and comparison.

• You definitely don't want greenlet for this purpose, because it's a low level library on top of which you can create light thread libraries (like Eventlet and Gevent).
• Eventlet, Gevent and more similar libraries provide excellent toolset for IO-bound tasks (waiting for read/write on file, network).
• Likely, most of your GUI code will wait for other threads (at this point green/light/OS thread is irrelevant) to finish, which is a perfect target for above mentioned libraries.
• All green thread libraries are mostly the same. Try all and decide which one suits your project best.
• But also it's possible that you'll need to extract some things into a separate OS thread due to requirements of OS level GUI layer.
• Considering that and better implementation of thread lock in Python3 you may want to just stick with native threading module if your application doesn't need hundreds or more threads.