> That's very interesting and useful, but I don't think it fits the same use > case I was talking about. I want the ability to create some object that > exports an URL that I can put in an iframe. Then all requests from that > iframe for resources will dynamically call my javascript code. I could > implement the same logic that a server-side application does, but from local > code in my browser. > That's just the purpose of ServiceWorker :-) Only that from your message, I suspect you are asking about having the same functionality but only on the current session or maybe also only when the page is open, deleting it on reload. I don't know of anything like to this, the most similar ones would be FirefoxOS Browser API or Chrome FileSystem API, but nothing as powerful as ServiceWorker, sorry :-( They are talking about implementing the Fetch specification, maybe you would write them about allowing to be used someway the ServiceWorker functionality on a per-session basis, I find legitimate your proposition...
-- "Si quieres viajar alrededor del mundo y ser invitado a hablar en un monton de sitios diferentes, simplemente escribe un sistema operativo Unix." – Linus Tordvals, creador del sistema operativo Linux