Users don't want "simple temporary HTTP server". They just want to save and load their files like they do in a normal app. I think it is fine for the actual page to be online somewhere, it's the user's *files* I am talking about.
As a web app developer these are the APIs that would most help users of my software on Firefox:File System API calls like `showOpenFilePicker` and `showSaveFilePicker so users can use my web apps to manage their own files just like native apps. They ...
