This library aims to be the simplest and most efficient thing for what it does. And what it does is perfect for is managing communications with things that them

This library aims to be the simplest and most efficient thing for what it does. And what it does is perfect for is managing communications with things that themselves may be bound by I/O. Handling multiple threads to access multiple CPUs would make it far more complex. And frankly a single thread is plenty for handling, say, a chat server.