libfiber

The high performance c/c++ coroutine/fiber library for Linux/FreeBSD/MacOS/Windows, supporting select/poll/epoll/kqueue/iouring/iocp/windows GUI. Maintained by iqiyi on GitHub, where it has earned 817 stars from the community.

It's actively developed around coroutines, epoll, kqueue, and is a solid reference for anyone building with these tools.