I didn’t want to add yet another gem to my gemfile, especially one with native dependancies that is going to mess with all the other environments where this app is used (Mac dev, windows dev, Heroku). Since Mac OS X and Windows have a JS runtime shipped by default, and heroku has it’s magic, only the linux box needs it.
The best solution is to install nodejs as a library. That is DL, ./configure, make, sudo make install. Now my linux box has a JS runtime too.