We are the creators of Mongoose - the most popular embedded networking library.
Mongoose supports HTTP, WebSocket, MQTT, CoAP, DNS, mDNS/DNS-SD (local device discovery) - both client and server mode. It works on top of SimpleLink and provides quite rich networking functionality.
Together with the port, we provide an example for K64: mongoose/examples/NXP_K64 at master · cesanta/mongoose · GitHub
This article has step-by-step instructions: Mongoose embedded networking library on NXP Kinetis - Hackster.io
We are looking for a feedback, and requests for ports to other devices.