This is a not standalone server and client but a set of java libraries which help people to develop their own Lightweight M2M server and client. The project also provides a client, a server and a bootstrap server demonstration as an example of the Leshan API and for testing purpose.
This wiki contains all the official documentation about Leshan. This is not so much for now ... but we will enhance it !
To go futher look at the sidebar on your right. 👉