PHD gives you Passenger-based Heroku-like Deployment.

If you have Passenger installed on a desktop/server, you should be able to:

$ git clone git://github.com/remi/phd.git
$ cd phd
$ sudo ./phd_server_setup
$ sudo ln -s /path/to/this/dir/phd /usr/bin/phd # phd needs to be in your PATH

And then, from another machine, you should be able to:

$ cd my-git-directory-with-a-Rails-or-Rack-application
$ git remote add my-server [email protected]

Now all you need to do is create a .pushand file in the root of your application (which specifies commands that will be run on the server):

$ echo 'phd $0 myapp.myserver.com' > .pushand
$ git commit -a -m "added .pushand for PHD deployment"

Now, when you can push your repo to the server and it'll detect your Rails/Rack application, set it up on passenger, and run it!

$ git push my-server master

That's it! http://myapp.myserver.com should work (assuming you setup the DNS)

PHD is just 1 tiny script. PushAnd is what makes all of the git magic work.