An XML-based standard for electronic books and Web publishing from the International Digital Publishing Forum (www.idpf.org). Introduced in 1999 and officially known as the "Open eBook Publication Structure Specification" (OEBPS), Open eBook publications are not read directly by an e-book device. They are compiled into the e-book's proprietary format in order to optimize the content for the particular hardware. The Open eBook format, last updated in 2002, was the precursor to the Open Publication Structure (OPS) of 2007. See OPS, OpenReader and e-book.