Leo Koppelkamm releases Bruno, a lovely multilayered font that is pretty easy to work with. For that he developed an InDesign plugin, which fetches the colors from your swatches, and lets you use them for the background layer. Essentially it seems to be two text frames, but glued together, and instantly updated. You can track the text, underline it, rotate, resize, basically do pretty much everything you can do while using any other font. Better see it in action in this demo video.
While it's cool from a technological point of view, it is also a cute design, which would feel at home with anything kids-related. The last line in the image is how the glyphs actually look in this font — with alternates to make the background. How Leo didn't go insane while designing them, is beyond me. Anyway, it's great to see people pushing the boundaries of what's possible in typography.
Protip: get Bruno while on sale!