This was an experimental project started in the hopes to move all of Turtl's core logic to lisp, as a DLL, and have various platforms (desktop/mobile) load it.
It accomplished this with a fairly high level of success, however its continued existence could not be justified as platforms that ran HTML5 became more and more sophisticated.
As such, it has been retired and now lives as a reference, specifically for those interested in running a lisp app embedded in another platform.
This will be brief, but mainly the app is loaded as a DLL. The DLL includes nanomsg, and the loading platform uses this to set up communication channels between itself and the lisp app.
Essentially, everything is done via message passing, which must be set up on the loading platform's side (although once done, then it had full access to turtl-core's abilities).
This was tested and worked in what used to be node-webkit (now nw.js) as a native node module, and also on firefox's app platform.
It was never tested on any mobile platform, although in theory one could cross compile ECL and the other required libs for android/ios without too much trouble, then it's as simple as loading a third-party lib.