OPenn contains complete sets of high-resolution archival images of manuscripts from the University of Pennsylvania Libraries and other institutions, along with machine-readable TEI P5 descriptions and technical metadata. All materials on the site are in the public domain or released under Creative Commons licenses as Free Cultural Works. Images and metadata may be downloaded under the license assigned to each document.

OPenn hosted repositories: Abraham Lincoln Foundation of The Union League of Philadelphia; African Episcopal Church of St. Thomas; American Baptist Historical Society; American Philosophical Society; Benjamin Zucker Family Ketubah Collection; British Library; Bryn Mawr College, Special Collections; Christ Church Philadelphia; College of Physicians of Philadelphia, The Historical Medical Library; Columbia University, Rare Book & Manuscript Library; Columbia University, The Burke Library at Union Theological Seminary; Congregation Mikveh Israel; Drexel University College of Medicine, Legacy Center; Drexel University, Archives and Special Collections; Episcopal Diocese of Pennsylvania Archives; Folger Shakespeare Library; Franklin & Marshall College Library, Archives & Special Collections; Free Library of Philadelphia, Special Collections; Free Library of Philadelphia, The Rosenbach; German Society of Pennsylvania; Gloria Dei Church; Haverford College, Quaker and Special Collections; The Hill Museum & Manuscript Library (HMML); Historical Society of Pennsylvania; The Huntington Library; Independence Seaport Museum, J. Welles Henderson Archives and Library; La Salle University, Department of Special Collections; Lehigh University Libraries, Special Collections; The Library Company of Philadelphia; Library of Congress; Lutheran Archives Center at Philadelphia; Palmer Family Collection; Philadelphia Museum of Art; Presbyterian Historical Society; Princeton University Library; Private Collection A (Archimedes Palimpsest and the Galen Syriac Palimpsest); Saint George's United Methodist Church of Philadelphia; Science History Institute, Othmer Library; St. Peter's Church of Philadelphia; State Library of Pennsylvania, Rare Collections Library; Swarthmore College, Friends Historical Library; Temple University Libraries, Special Collections Research Center; University of Delaware Library; University of Manchester Library, Special Collections; University of Miami, Jay I. Kislak Collection; University of Pennsylvania Archives and Records Center; University of Pennsylvania Libraries; University of Pennsylvania Libraries, Lawrence J. Schoenberg Manuscripts; University of Pennsylvania Museum of Archaeology and Anthropology; University of Pennsylvania Museum of Archaeology and Anthropology, Archives; University of Pennsylvania School of Nursing, Barbara Bates Center; Villanova University Libraries, Special Collections; and The Walters Art Museum.