RailRoad is a class diagrams generator for Ruby on Rails applications.
$ sudo apt-get install graphviz
$ sudo gem install railroadGenerating models diagram in .dot file format and converting it to png:
$ railroad -o models.dot -M
$ dot -Tpng models.dot > models.pngModels diagram in svg format.
$ railroad -M | dot -Tsvg > models.svgModels diagram with all classes showing inheritance relations
$ railroad -a -i -o full_models.dot -MControllers diagram in png format.
$ railroad -C | neato -Tpng > controllers.png