ActsAsTaggableOn is a tagging plugin for Rails applications that allows for custom tagging along dynamic contexts.

This plugin was originally based on Acts as Taggable on Steroids by Jonathan Viney. It has evolved substantially since that point, but all credit goes to him for the initial tagging functionality that so many people have used.

For instance, in a social network, a user might have tags that are called skills, interests, sports, and more. There is no real way to differentiate between tags and so an implementation of this type is not possible with acts as taggable on steroids.

Rather than tying functionality to a specific keyword (namely “tags”), acts as taggable on allows you to specify an arbitrary number of tag “contexts” that can be used locally or in combination.