This library uses the ESP32's LED control peripheral to control a simple buzzer connected to one of the board's pins. It's really small and allows for simple funcionality like setting the output frequency, stopping and starting the buzzer and playing sounds for certain amount of time. It also has the capability of playing musical notes, and even playing melodies defined in a way similar to their natural musical notation.
This is a work in progress, and still lacks thorough testing and documentation.