I have found at least one framework with the necessary features for implementing the kind of system asked for in the question.
os.js
is a Javascript framework with a "web desktop implementation for your browser with a fully-fledged window manager, Application APIs, GUI toolkits and filesystem abstraction.". As such, it has the essential features needed to craft a rich desktop environment, along with an underlying toolkit helping to tie it to backend functionality.
This is a good, extendable starting for crafting more basic solutions.
Reference: http://os.js.org/