Ruby on rails (RoR)

(From the perspective of an absolute beginner)
It looks like a programming/scripting language that is designed to retrieve (from files and databases) and present (on websites and mobile applications) data.
It is used in some very popular applications, like Twitter.
It seems to have a religious, cult-like following who try to convert non-believers into users.

First taste
Googling for some info about this language (or framework or whatever) led me to: tryruby.org.  This site was mildly entertaining and it served its purpose of enticing me to learn more about RoR.  Actually, I liked the embedded command line prompt in the browser, so assuming that ruby was used to build that site, it seemed like RoR was something worth learning.

Installation
I'm following this tutorial:
http://coding.smashingmagazine.com/2011/06/21/set-up-an-ubuntu-local-development-machine-for-ruby-on-rails/
It looks like I need to install and use git.  I've read a bit about this version control system, and it sounds quite intimidating.  I'm excited to learn about it, which must make me a bit of a nerd.
In the end, it looks like I've installed:

git = open source distributed version control system
rvm = ruby version manager
ruby =  dynamic programming language
gem = ruby packaging system
rails = a framework to build web apps with ruby
capistrano = tool for running scripts on multiple servers
postgresql = database management system

This seems like a lot of stuff to get going.