.OPF File Extension

An OPF file is a FlipBook specification file created by E-Book Systems FlipViewer. It contains XML-format data that defines and organizes a FlipBook's content.

FlipViewer is a content viewing and publishing application that allows users to create and save digital magazines, catalogs, and other forms of eBooks. The app saves these eBooks, known as FlipBooks, in the OEB Package Format (OPF). These packages consist of an OPF file and imported content files (such as images).

Alternatively, users can save FlipBooks in the .OPZ format. An OPZ file is a single, zipped file that includes a FlipBook's OPF file and all referenced content files.

You can open an OPF file with E-Book Systems FlipViewer and Mac FlipViewer. In FlipViewer, you can view the FlipBook an OPF file describes.

You can also open an OPF file with Microsoft Notepad (Windows), Apple TextEdit (Mac), or any other text editor, to view the XML data it contains.

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.

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

NOTE: FlipAlbum has been discontinued and is no longer available for download.

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.