Nice project. Have you guys looked at ql.io?
With webshell, we are more focused on services execution, as for client side as server side.
For example we enable custom HTML views for GoogleMaps, Google Chart, Twitter feeds or other APIs.
The main difference is that we combine all kind of APIs. We also made a platform on top of the language.
This plaform enables to re-use each script as a new REST/JSON API by other developers, thanks our file system designed as a kind of "Github for APIs."