Download
There are quite a few ways to get your hands on the various engines available. The first thing to do in any case is to get the Engines plugin itself, which is what we'll cover here.
Rails' own script/plugin command
The first thing to do is update the plugin command's list of download sources:
$ ruby script/plugin discover
Now we can install the actual Engines plugin:
$ ruby script/plugin install engines
Alternately, you can explicitly specify the location from which to download and install the engines plugin:
$ ruby script/plugin install http://svn.rails-engines.org/plugins/engines
From this point you can now install plugins as normal - any additional files each plugin provides will automatically become available when your Rails application loads.
SVN
Developers using SVN will probably find it much more convenient to use SVN itself to include engines (and plugins) in their applications. The Rails Engines repository can currently be found at http://svn.rails-engines.org/. The layout for this repository is discussed here.
SVN Externals
SVN externals are an ideal way of including code from other repositories in your own application. The basic commands for including the Engines plugin into your plugins directory via SVN externals are:
$ cd PATH_TO_YOUR_APP $ svn propset svn:externals "engines http://svn.rails-engines.org/engines/tags/rel_1.2.0" vendor/plugins
It is highly recommended that you use tags if you are deploying business-critical applications, since there is some chance that any changes to the trunk or any subsequent releases will negatively affect your application. Alternatively, you could use the Piston tool.
For more information run:
$ svn help propset