The collection contains Islamic teaching material that has been in use in the Riyadha mosque since its foundation in the late 19th century. It covers all Islamic disciplines, such as fiqh, tawhid, nahw, mantiq and Sufism. The Sufi content reflects its close connection with the Alawi tradition of Hadramawt, established by Saleh b. Alawi Jamal al-Layl, the founder of the Riyadha. Some of the manuscripts in the collection were his personal property. The collection consists of manuscripts dating mainly from the 19th and early 20th century. The earliest dated manuscript (EAP466_RM77) dates from 1162H/1748CE. The majority, however, dates from between 1860 and 1920, which is also the foundational period for the Riyadha mosque.
The collection consists of 149 manuscripts of varying size. Of these, 134 have been digitized for the EAP project.
Language of the material is in Arabic. Three manuscripts have additional text in Swahili in the Arabic script.