I'm pleased to announce the release of Hydra 9.0.0!  This is the first
release of the Hydra gem for Fedora 4 and represents almost a year of
effort.  In addition to working with Fedora 4, Hydra 9 includes many
improvements and bug fixes. Especially notable is the ability to add RDF
properties on repository objects themselves (no need for datastreams) and
large-file streaming support.

Additionally, several supporting gems have major version upgrades to work
with Hydra 9:

hydra-collections 4.0.0 (
hydra-derivatives 1.0.0 (
hydra-editor 1.0.0 (
sufia 6.0.0.rc3 (

If you are planning on upgrading your repository from Fedora 3 to Fedora 4,
there is a project started by Penn State called fedora-migrate that you
should have a look at: At
this point they are able to automatically migrate 98% of there objects to
fedora-4 without any intervention. We would appreciate your help making
this project get even better results.

Release notes:

If you're interested in having a test drive take a look at the Hydra
tutorial:  This
material will be presented at a code4lib pre-conference afternoon workshop
next week.  Sign up here:

Justin Coyne
Data Curation Experts