The International Digital Publishing Forum (IDPF) was a trade and standards association for the digital publishing industry, set up to establish a standard for electronic book publishing. It was responsible for the EPUB standard currently used by most e-readers.
Starting from the Open eBook Publication Structure or "OEB" (1999), created loosely around HTML, it then defined the OPS (Open Publication Structure), the OPF (Open Packaging Format) and the OCF (Open Container Format). These formats are the basis for EPUB.
While the basic standards are now established (pages, hyperlinks, definition of table of contents, authors, etc.), some other standards intersect the hardware field, such as those for power and for features of the hardware reader devices, and are still undergoing change and evolution. Other standards for ecommerce (including Digital Rights Management), are tied to the way the ebook is sold or delivered, and are therefore controlled by vendors.