This is a Heroku buildpack for Firefox. Meant to be used in combination with something like xvfb, for headless operation.
Example usage:
$ heroku create --stack cedar --buildpack http://github.com/evosystem-jp/heroku-buildpack-firefox
# or if your app is already created:
$ heroku config:add BUILDPACK_URL=http://github.com/evosystem-jp/heroku-buildpack-firefox
$ git push heroku master