From the project website (accessed 2016-01-08):
The Arabic Papyrology Database is a tool enabling you to access the editions of Arabic documents written on different material such as papyrus, parchment or paper. Those productive editions are an often unraised treasure for almost every aspect of Islamic history up to the 16th c. A.D.
The APD comprises a total of 8845 documents. For 2573 out of these, we give both the full and the metadata, while for 6272, we give the metadata only. The tool 'Documents' allows to search for documents and read their text in different layers. The tool 'Search' accesses single words or combinations of words - perfect for investigating linguistic peculiarities. The tool 'Lexicon' gives you direct access to all of the lexicon, incl. Greek, Coptic, etc. words. Each document is also provided with its metadata, amongst others place and date of origin or its genre as for instance a contract of lease or a petition.
The Arabic Papyrology Database is the first electronic compilation of Arabic papyri. It is a non-commercial project running under the patronage of the International Society for Arabic Papyrology (ISAP) and a partner of the Trismegistos metadata project of Greek, Demotic, Coptic, Arabic, etc. documents. Access is free via the Internet.