At the moment, when Epiphany cannot open a file itself, it defaults to downloading it file and then telling an application to display that local copy. This can be wasteful and inconsistent.

The application which opens that file is now unaware that it belongs at a particular location on the web. If that file contains relevant links to other things from the source (which Epiphany would not have downloaded) the user will be very confused.

Automatically downloading the remote file breaks consistency so the user cannot always click seamlessly through a particular task. It turns Epiphany into the only application capable of accessing content 'directly' on the Internet, which should not be the case. We have been blessed with the wonderful tool gvfs. Many applications in GNOME (including Evince!) support it, and I am sure the number would grow with the awesome incentive of working seamlessly with Epiphany.

So, instead of Epiphany always downloading files to /tmp and then telling apps to open them, we should allow the individual applications to handle getting remote files for themselves by passing them full-fledged URIs to the locations Epiphany finds via http. This makes sense for types of web pages that Epiphany cannot understand, video streaming... all sorts of stuff. It also would keep /tmp tidy and encourage a more modular, streamlined design throughout GNOME.