The JRubyArt LibraryLoader module is essentially the same as that developed for ruby-processing. But since processing-3.0 there is the distinct possibility that you will need to specify the vanilla processing sketchbook folder (in .jruby_art/config.yml), for it to work properly. As a convenience you can call the module using either load_library or load_libraries from your sketch. The preferred way call the library / libraries is as a symbol, comma separated list of symbols but Strings also work see below for core java libraries:-

load_library :sound
load_libraries :sound, :pdf
load_library 'sound'
load_libraries 'sound', 'pdf'

To use classes from the sound package say with full-qualified class name use:-

generator =

To avoid using the full-qualified class name use include_package

include_package 'processing.sound'

generator =

The contributed processing libraries are called in the same way, as well as ruby libraries such boids and control_panel the latter being a bit of a hybrid.

load_library :control_panel
load_library :boids