Hi Matt, 

The Islandora Community (http://islandora.ca/about) is releasing some lovely open source digital repositories. Islandora is interoperable and extensible through the Tuque API, the Islandora OAI module, and many other tools that are included in the software stack. 

Here are a few repositories to explore: 
http://dcmny.org/
http://dlib.bc.edu/
http://repository.lib.cuhk.edu.hk/
http://arcabc.ca/

We have monthly webinars on Islandora if you'd like to join and learn more. 

~ Erin 

Erin Tripp, BJH MLIS 
Business Development Manager
discoverygarden inc. 
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