One of Vim's strengths is its extensibility, allowing each user to achieve a personalized setup that is ideal for their needs and preferences.  But this customizability is a double edge sword, because there is a lot of work to do in order to turn a basic Vim install, into a tricked out Vim-based ruby IDE.  A novice can spend a week just trying to figure out what plugins they need, how best to set them up etc.

This project is meant to be a jumpstart, to just get up and working with a Vim that has it all for Ruby development.  You may prefer different key mappings etc.  But at least you will have a fully specified Vim for Ruby IDE, which you can easily tailor from this starting point.

Follow these MacOS-specific steps:

1. Install Ruby

   More than one way to get Ruby setup, but I recommend installing RVM and having RVM install a ruby version for you. Also, make sure you include the ruby debugging gems in your gemset, for example:
  
    $ gem install ruby-debug ruby-debug-ide

2. Install Homebrew

   Homebrew for MacOS is a tool that builds and installs software.  Make sure you have it installed for the next step.

3. Install Vim (must install with Ruby, Python and clientserver support enabled!)

    You have to do a custom build of Vim, because the binary version of MacVim on the web is built with ruby disabled.  To build a ruby, python an clientserver enabled version of Vim, just let Homebrew do its thing:

    $ brew install vim    # homebrew builds with ruby enabled by default

4. Run update_bundles

   This will download and install all Vim plugins I have found to be useful as part of a Vim IDE for Ruby.

5. Copy or merge .vimrc and .gvimrc to your HOME directory

   Copy in whole or in part the .vimrc and .gvimrc files included in this project to your HOME directory.  While you
   may want to skip parts or use your own key mappings, at least make sure that the pathogen section is reflected
   in your .vimrc file and positioned at the top.  Otherwise, no plugins will load.

6. Start Vim

   Once you start Vim, press Command-o.  If the NERDTree file explorer pops up, everything is ready.

That's it.

NOTE: MacOS is the only platform I have tested these steps on so far.

CREDITS:  The update_bundles script was copied (with little change) directly from Tammer Saleh's blog at:
           http://tammersaleh.com/posts/the-modern-vim-config-with-pathogen