Anjay is an LwM2M SDK that enables the LwM2M protocol on any hardware device. It features a completely internal implementation of CoAP and is able to run on any kind of platform. The product is released as an open-source and available at: https://github.com/AVSystem/Anjay.
Commercial options which include support and advanced features are also available as a terminator T800.
Anjay's technical details: