I know there are more folks interested in going the other way -- seeing libferris through kio glasses. Not that there are hoards of folks in either camp of course. Nonetheless the first move has been to allow libferris to mount kio.
The groundwork is very similar to what I'm thinking of using to allow kio to mount libferris. Top level URL schemes will appear first, allowing you to dig into each URL scheme. For example, in libferris kio appears under the kio: filesystem. The first directory in that filesystem is the KIO URL scheme to use. So something like the following will work:
$ date >| /tmp/df.txt
$ fcat kio:file:/tmp/df.txt
Some of the more fun KIO slaves to access through this are the man and fonts URLs. The following two commands produce the same man page:
$ fcat kio:man:/man
$ kioclient cat man:/man
Support is preliminary and only allows reading the files but not writing to them through the kio: filesystem as yet. Already though the kio: can be exposed to XQuery, SQLite, and through the libferris REST interface. Yay for cooperating!
I notice some really juicy digikam kio slaves but haven't dug into them enough to use them as yet. Although you can already upload to various web services from digikam, once I get access to digikamalbums through ferris kio mounting I can then 'cp' the images directly from the command line to other things that libferris can already mount such as flickr API sites, printers etc.