For historic reasons, Chrome uses the Extension system, more specifically “Bookmark Apps”, to create and install apps based on websites. Hosted Apps are getting deprecated, so we will eventually migrate off extensions/ and into web_applications/, but in the meantime we still need to add new features to the current implementation.

This directory holds files that implement new features for Hosted Apps that will soon be moved to web_applications/. This is to avoid adding files that will soon be deleted to extensions/ folders.