gistfile1.rb

# Apple Script to open google in a new tab
#  tell application "Safari"
#    make new document
#    set URL of first document to "http://www.google.com"
#  end tell

# rb-appscript to do the same
#  app("Safari").make(:new => :document)
#  app("Safari").documents[1].URL.set("http://www.google.com")

# MacRuby code to use the ScriptingBridge to do the same
framework 'ScriptingBridge'
require 'hotcocoa'
include HotCocoa

safari = SBApplication.applicationWithBundleIdentifier('com.apple.Safari')
#safari.make(:new=> :document) # <-- FAIL
safari.documents.first.URL='http://www.google.com'