I want to use org-mode files in one of the many Ruby static website generation tools (Webby, Webgen, Jekyll, etc.). Thus, I needed a way to extract simple HTML from an org-mode file without relying on emacs.
Thus, org-ruby was born. It's not nearly as full featured as the emacs-based HTML export, but at the moment I am successfully using org-mode files as content for Webby static websites.