An article in the current Dlib Magazine describes how we built the OCLC Research Publications Repository. We took a lightweight modular approach which leveraged a variety of capacities to expose the repository content through a variety of routes. It contains materials going back over twenty-five years.
Our repository was built using lightweight, modular, inexpensive services, and we found these to be highly flexible in building our repository. At the repository manager’s end, the only requirement is to catalog items into WorldCat. For that effort, the consumer gets all this magic: RSS, OAI, SRW/U, ERRoLs. [OCLC Research Publications Repository]
We used OCLC services for metadata creation and, in some cases, for archiving; aspects of the approach could be replicated in another environment.
See the repository user interface here, and find more details on the About page.