The software that powers my photo archive (aptly named Photo Organizer) hasn't seen much attention in the past few years or so. That's mostly because it does what I need with little fuss, and the other users either don't exist any more or are satisfied with what it is.
The other reason it hasn't seen much attention is that there's so much tecnhical debt in that codebase that all of the substantial feaures I have on my eventual to-do list require some major plumbing work.
So, the result is that in the past three or so years, development's slowed to a trickle of bugfixes. The notable exceptions are addition of a few more esoteric image formats, and updating the default themes to take advantage of now-common CSS3 constructs. Not exactly earth-shattering!
Last night, I finally sat down and added a major new feature, a (read-only) JSON-RPC interface that exposes the same sorts of information as the RSS feed generator.
My primary goal is to enable gnome-photos to directly interface with Photo Organizer, but this JSON-RPC interface will enable many more things. Unfortunately the data exported through the RPC API is far from complete, but I only see that improving as I figure out what to do with this thing.