HathiTrust bibliographic metadata, page images, OCR generated text, etc. can be retrieved via the HathiTrust Bibliographic and Data APIs (more here):
The Bib API returns bibliographic, copyright, and volume information (including permanent URLs) when queried with a variety of standard identifiers (e.g., ISBN, LCCN, OCLC, etc.). The API has controls to return brief or full bibliographic metadata.
Data (page images, OCR text, and associated metadata)
HathiTrust has developed a Data API that makes it possible to retrieve page images, OCR text, rights information, and a variety of other data about objects in the repository. A draft specification for the API has been made available for comment from the HathiTrust partners. Please read the most recent Monthly Update for current status information."
Digitized manuscripts from the Islamic Manuscripts Collection at the University of Michigan appear in HathiTrust (cf. Islamic Manuscripts (Michigan) collection) and thus descriptive data and images for those manuscripts can be retrieved using the Bibliographic API and Data API described above. OAI can also be used to harvest the bibliographic records.