rails_rrdtool is a Scripts software developed by Josh Rendek. After our trial and test, the software is proved to be official, secure and free. Here is the official description for rails_rrdtool:

MarydownEditor: Rails_rrdtool is a Ruby on Rails plugin that provides a ruby-like interface to the RRD program. All variables and hashes sent to the tool are shell escaped so there is no worry about bad input. This is what Servly uses to manipulate RRDs.