This is the sample application for Ruby on Rails Tutorial: Learn Rails by Example by Michael Hartl.
I am using RubyMine instead of Sublime Text 2 as my editor/IDE. Check out tips on using RubyMine in this project's wiki
For editing Markdown there are a number of options. Just go to Mac App Store and search
for markdown. Mou is not at the MAS but is availiable
and is free. I personally like a combination of Multimarkdown Composer and Marked
and both are available from the MAS. Marked is just a previewer and
works with any editor, plus it has a
GitHub style for previewing. Multimarkdown Composer handles both Markdown and
Multimarkdown syntax. GitHub's syntax is in between but closer to [Multimarkdown].
There is even a Markdown plugin for RubyMine which I am using for editing
this README.md file.