I build a digital signage platform based on the Raspberry PI. It started as an open source "for fun" project (https://github.com/dividuum/info-beamer) but has now evolved into the most powerful software to build animated, hardware accelerated visualizations on the PI. As using the software on its own can be complicated (if you're not a programmer) I built a complete SaaS around it (https://info-beamer.com/hosted) which allows you to get your first screen running in a few minutes without any knowledge of Lua, Linux or even the PI. The software running on the PI is written in C/Lua and uses OpenGL/OMX to do its hardware acceleration. The hosted service is built using Python and includes a complete readonly and custom built Linux distribution that runs on the PI. On top of that it's possible to control the hosted service using the API so you can build your own digital signage around the technology. It's so much fun developing on all different parts of the product that I'll never get bored.