etherplay-cli is a command line tool for game developers to emulate the Etherplay environment in order to develop games.
It currently has only one command (serve) :
etherplay serve <game file path> [<port>]
that spin up a local server serving an etherplay enebaled web page that embed the specified game file and serve all the other files contained in the containing folder.
You then just need to browse at http://localhost:<port> which by default is : http://localhost:8080
To find more info about Etherplay, have a look at http://etherplay.io
The idea behind etherplay is explained at http://etherplay.io/#developers
And the api documentation can be found at http://etherplay.io/documentation