Chrome is the entirety of entities making up the user interface of a specific application or extension.
A chrome package consists of a set of chrome providers. There are three basic types of chrome providers:
- Locale. Translations for multi-language support. The two main types of files are DTD files and java-style properties files.
- Skin. The skin provider provides complete appearance data for the user interface. Consisting of CSS files and images.
(Note that while both of the documents below mention <tt>contents.rdf</tt> files, an easier way of registering your chrome providers - using Chrome Manifests - is supported since Firefox 1.5 / Toolkit 1.8)