Libwebsockets is a simple-to-use, MIT-license, pure C library providing client and server for http/1, http/2, websockets, MQTT and other protocols in a security-minded, lightweight, configurable, scal
A small embedded Modbus protocol stack, written in C language, support master and slave, support discrete mapping, support non-blocking and blocking read and write mode, and provide a complete example, can be transplanted to different processors, simple to use, portable.