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ActiveFedora is a Ruby gem for creating and managing objects in the Fedora Repository Architecture
Getting Started with ActiveFedora
ActiveFedora Tutorials and Reference
Hydra Derivatives
hydra-derivatives is a Ruby gem that provides derivative generation for Samvera repositories
Getting Started Additional with hydra-derivatives
hydra-derivatives additional details regarding FFMpeg and video transcoding
Hydra-Head
Hydra-Head is a Ruby-on-Rails gem containing the core code for a web application using the full stack of Samvera building blocks.
IIIF Manifest
IIIF http://iiif.io/ defines an API for presenting related images in a viewer. This transforms Hydra::Works objects into that format usable by players such as http://universalviewer.io/
LDP (Linked Data Platform)
Linked Data Platform client library for Ruby