This CD-ROM continues the ongoing collaborative project devoted to the electronic publication of the medieval and Renaissance witnesses to William Langland's Piers Plowman. The edition of the B-version manuscript known as R' is especially important because of its status as the only reliable witness for one of the two surviving branches of the B tradition. As is usual for the series, the edited text of the manuscript is presented in four different views -- a diplomatic type-facsimile; a scribal text with indications of scribal error; a critical text with lapsus calami corrected; and an AllTags view that shows all of the editorial interventions on one screen -- along with color facsimiles and hyper-textual linkages to enable the display of the complex relationships to other B witnesses. Robert Adams is Professor of English at Sam Houston State University.