Install Rails 4 correctly on OS X Mountain Lion

After reading several books and tutorials on Rails, I found it difficult to get a step by step guide to set up Rails on OS X. Most of what I read is just speeding through the steps and many of them don't work as expected for various reasons (no compiler installed, outdated version of curl, etc). So I wrote a detailed step by step on my blog here:

I successfully installed Rails on 5 machines so far using this proposed way. Maybe newcomers can benefit from it.

Have a great day!

I usually use - a single command install for an entire rails development setup.