RubyMine is a nice Ruby-centric IDE. It includes a lot of features that are peripheral to Ruby itself, including support for Rails, git, Sass, HAML, Slim, and CoffeeScript.

While many Rubyists don't like IDEs, this is probably the most acceptable IDE for Ruby, by far.

RUBYMINE_VERSION='4.5.4'
 
# Download the DMG file.
wget http://download.jetbrains.com/ruby/RubyMine-$RUBYMINE_VERSION.dmg
 
# Mount the DMG file.
hdiutil attach RubyMine-$RUBYMINE_VERSION.dmg
 
# Copy the app file into the Applications folder.
cp -a /Volumes/RubyMine/RubyMine.app /Applications/
 
# Unmount the DMG file.
hdiutil detach /Volumes/RubyMine
 
# Add a dock icon.
dockutil --add /Applications/RubyMine.app
 
# Delete the download.
rm RubyMine-$RUBYMINE_VERSION.dmg

We sometimes like to make edits and not save them until we're ready. To do this, we have to turn off one of the auto-save features:

• General
  • UNCHECK Save files on frame deactivation

I don't like the cursor to be in "no man's land", outside of the actual content. So we can turn that off:

• Editor
  • Within Virtual Space:
    • UNCHECK Allow placement of caret after end of line

Some programs have difficulty dealing with text files without a line feed as the last character. (Some argue that the standard says that it's not a text file if every line does not end with a line feed.) We can force the editor to ensure that the last line contains a line feed:

• Editor
  • Within Other:
    • CHECK Ensure blank line before end of file on Save

We like to always see line numbers:

• Editor
  • Appearance
    • CHECK Show line numbers

We want to start with an Eclipse-based keymap, and customize some things. So start by creating a keymap named BoochTek:

• Keymap
  • Keymaps: Eclipse
  • Hit the Copy button, and type in "BoochTek"