Web Server Core of 40kb. Minute static and runtime footprint.
Cross-platform: Linux/Unix, MacOS, QNX, eCOS, Windows, Android, iPhone, FreeRTOS (TI CC3200, ESP8266), Embedded Linux
Built-in Protocols: Plain TCP/UDP, SSL/TLS, HTTP client/server, WebSocket client/server, MQTT client/broker, CoAP client/server, DNS client/server, async DNS resolver
Copy two files into your build tree. Access to source code so you can fully trace the code