Hello, you'll probably think this is a "too early" request, but very recently the WebP format has gained a lot of exposure and popularity due to the adoption/support in newer versions of Opera and Chrome (and I think is matter of time for Firefox to do the same).
WebP is a very good format already, with significantly better compression/quality ratio than JPEG, which makes it perfect for web content... And I thing it already has reached a very usable status... Is supported by a good deal of development, tools, libraries...
So I think RIOT could implement such a format without too much hassle.
What do you think?