mapsberry is a Ruby on Rails app but it simply opens a window on to Ordnance Survey’s OpenView server. I wanted to try a more complex RoR app on RPi so I ported my TreeViewer family tree site from its normal home at dalriada.org.uk.
That involved upgrading it from Rails v2.3.5 to v3.2.7, which is not as easy as it sounds. Eventually the result was fine, but its Mongrel server only runs on my Arch Linux pi. Check it out at dalriada84epa.plus.com:3001 .