.OPF File Extension

File formatted according to the Open Packaging Format (OPF) standard, which is part of the EPUB eBook specification; stores eBook information such as the title, language, book ID, creator, reading order, and display formatting; used as part of an .EPUB archive to specify eBook metadata.

OPF files are saved in an XML format. The Open Packaging Format standard also requires a second .NCX XML file that stores the table of contents for the EPUB eBook.

Digital photo album created by FlipAlbum, a program that organizes images into picture albums; stores the album structure, appearance settings, and references to image files; can be viewed with 3D page-flipping effects.

FlipAlbum photo albums are commonly used for sharing pictures with friends and family. Professional photographers also used them for arranging pictures for clients.

NOTE: OPF files are saved in E-Book Systems' proprietary FlipAlbum XML format, and should not be confused with the Open Packaging Format (OPF) standard.

FlipBook, such as a digital magazine or other publication that can be read with FlipViewer; saved in the OEB Package Format (OPF) which is formatted in XML; includes metadata that describes the content and a list of pages, images, and text referenced by the publication.

Because OPF files are formatted in XML, they can be created and edited with a basic text editor.