> modern times to run php, people would use php-fpm with nginx, it is running multiple worker (single) process, so why would anyone [2], [3] wants multi-core co

> modern times to run php, people would use php-fpm with nginx, it is running multiple worker (single) process, so why would anyone [2], [3] wants multi-core coroutines in it? What does it even mean? Not everyone does. There's also https://reactphp.org https://reactphp.org (which is an event loop runtime, similar to Node), and https://amphp.org https://amphp.org (also event loops), and Swoole https://github.com/swoole/swoole-src https://github.com/swoole/swoole-src (coroutine runtime, similar to Go). Fibers are basically an API that event-loop runtime libs can use so that userland code doesn't need to use promises or generators to run non-blocking operations. Fibers are not useful for php-fpm or swoole users.