Example applications built on top of eZ Exceed.
You simply install the extension itself, and you will get two new toolbar buttons in Exceed.
The Twitter example show how simple including a twitter widget can be.
Its the ultimate lightweight implementation if you have some HTML to present in an iframe.
This is a from-the-ground-up JavaScript module that shows that you can really do whatever you wish,
and that the boilerplate code is tiny.
If you know a bit of AMD/Require.js and Backbone.js you can write anything using this approach.