gifs in slideshow or screensaver
I made a tiny screensaver that can play GIF's and can run in background. It is free and I upload the source code to Github so that every one can look how it is done and participate in further development. 

Here is the Github project page: 
https://github.com/Waitsnake/AnimatedGif 

And here a ZIP of the compiled screensaver can be found: 
https://github.com/Waitsnake/AnimatedGif/releases/latest/