Using the Coge webkit plugin for quartz composer it is as easy as make a QC comp with the webkit plugin linked to a billboard and loading it into modul8.
You would need the QCRehab plugin from Kineme to load the comp properly inside Modul8.
If you wish to control and navigate the web/HTML while in Modul8 you should have to do it at QC and send it to Modul8 via Syphon:
Make a QC comp with the Coge webkit plugin, a mouse patch linked to it (so you can navitagate through the website with the mouse) and the Syphon server for QC.
On the other side make a QC comp just with the Syphon client linked to a billoard and load it in Modul8.
Of course you should put the same server name in both the server and the client, and "Quartz Composer" on the "Application" field of the client.
If you want to render a local file you should put the file:///Users/user/Desktop/whatever_folder/file.html stuff.
You could ajust the width and height on the webkit plugin to the divs or so and you would have no scrollbars at all
Actually I tried this to render a vvvv.js patch inside Modul8, it wasn't the most fluid image on the world but it was ok.
Hope it is usefull for someone.