anchor.diff:  Each entry in that repository is identified by a key, and that key is the `pluginKey`.
   * Third party plugins: For third party plugins, the key is specified at the time the plugin gets installed. The key must be of the form `<prefix>::<something>` to make sure there is no name collision with Kill Bill plugin keys.
   
  -TODO: provide example of installing such plugins.
  +
  +=== Java Plugins
  +
  +TODO: 
  +
  +=== Ruby Plugins
  +
  +==== Prerequisites
  +
  +Ruby 2.1+ or JRuby 1.7.20+ is recommended. If you don't have a Ruby installation yet, use https://rvm.io/rvm/install[RVM]:
  +
  +[source,bash]
  +----
  +gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
  +\curl -sSL https://get.rvm.io | bash -s stable --ruby
  +----
  +
  +After following the post-installation instructions, you should have access to the `ruby` and `gem` executables.
  +
  +Install the following gems:
  +
  +[source,bash]
  +----
  +gem install bundler
  +gem install jbundler
  +----
  +
  +==== Build
  +
  +Follow these steps, making sure each one is successful before moving on to the next one:
  +
  +[source,ruby]
  +----
  +rm -f Gemfile.lock Jarfile.lock .jbundler/classpath.rb
  +bundle install
  +jbundle install
  +# Cleanup output directories
  +bundle exec rake killbill:clean
  +# Build your plugin gem in the pkg/ directory
  +bundle exec rake build
  +# Build the Killbill plugin in the pkg/ directory
  +bundle exec rake killbill:package
  +----
   
   === Deploying by Hand
  +
  +==== Java Plugins
   
   For `java` plugins, deploying by hand consists in building the self contained OSGI jar, and copying that jar at the right location. For example, the `adyen` plugin with a version with version `0.3.2` would show up as the following:
   
  
positive.code: 
  The file `plugin_identifiers.json` is used to keep a mapping between the `pluginKey` (the user visible plugin identifer), and the `pluginName` (runtime identifier used by Kill Bill when scanning the filesystem). The next section provides more details about those.
  
  === Plugin Coordinates, Plugin Key, Plugin Name...
  
  Today, both our `ruby` and `java` plugins are released through maven and are therefore identified through their maven coordinates.
  We might support other schemes in the future but today this is the only way we offer to download and install publicly released plugins.
  
negative.code:     |_tmp
  ```
  
  In order to make it easy to deploy those plugins we created a special rake task that will copy, untar plugin entries at the right place:
  
  [source,ruby]
  ----
  # Optional: deploy the plugin (and clobber a previous version if needed) in /var/tmp/bundles.
  # Alternatively, you can manualy deploy the .tar.gz or .zip artifact from the pkg/ directory
  bundle exec rake killbill:deploy[true]
  ----
  
  Note that if you don't need any custom configuration, make sure to delete the default YAML configuration file `/var/tmp/bundles/plugins/ruby/killbill-\*/*/*.yml`. In development mode, i.e. when you are running tests outside of Kill Bill (see `rake test:spec` and `rake test:remote:spec`), the database configuration is specified in that YAML file (payment plugins rely on a couple of database tables, principally to keep the credit card tokens and gateway-specific details for transactions, such as reference codes). By default, the plugin will use SQLite. If you uncomment the part of the YAML file below the comment "In Kill Bill", this will tell the plugin to use the JNDI connection exposed by Kill Bill instead. This is the default in case the file isn't present (or if the database section is missing).
  
  
  Also, in the case of `ruby` plugin (and as mentionned before), the correct version of the `jruby.jar` must exist (and be name that way) under the `platform` directory entry. The correct version must match the Kill Bill version (or more precisely the version of the https://github.com/killbill/killbill-platform[platform] used for the a specific version of https://github.com/killbill/killbill[killbill]).
  
  
  === KPM
  