To be honest I've always wanted a file format that is exactly as you described. A zipped up front end web app. No internet dependencies so it works 100%. User can open the open the format and it opens in their browser of choice. All the files contained within are "hosted" from a static "webserver" that just hosts the files within the .zip.
I can't say much to WinJS yet, but I am interested in their choice of container.
I can't say much to WinJS yet, but I am interested in their choice of container.