In RVM, Ruby’s version management system, I installed Heroku in gemset global, which can be used from any gemset state.

$ rvm gemset use global
Using /Users/your_username/.rvm/gems/ruby-1.9.2-p290 with gemset global

$ gem list

*** LOCAL GEMS ***

bundler (1.0.22)

$ gem install heroku

That’s all from the Gemba.