A helper is a concept employed in many application frameworks, including Kohana. It is a class that contains helpful static methods grouped together around a single concept. Kohana comes with a wide range of useful helpers, and each Gallery 3 module can provide its own. For more information including detailed examples, refer to Kohana’s documentation on Helpers. One caveat on Kohana’s docs is that in Gallery 3, all helpers should be associated with a module and live in the module’s helpers directory.
Note that library class names must start with an lowercase letter for the Kohana Cascading Filesystem to find them properly.