Open eBook (OEB), or formally, the Open eBook Publication Structure (OEBPS), is a legacy e-book format which has been superseded by the EPUB format. It was "based primarily on technology developed by SoftBook Press". and on XML. OEB was released with a free version belonging to public domain and a full version to be used with or without DRM by the publishing industry. Open eBook is a ZIP file plus a Manifest file. Inside the package a defined subset of XHTML may be used, along with CSS and Dublin Core metadata. The default file extension is .opf (OEB Package Format). Specification release history September 2007 – Open Publication Structure (OPS) 2.0, EPUB. Released, supersedes the OEBPS 1.2 August 2002 – OEBPS 1.2 Recommended Specification Released June 2001 – OEBPS 1.0.1 replaces OEBPS 1.0 September 1999 – Open eBook Publication Structure (OEBPS) 1.0 released Reader software SoftBook Adobe Digital Editions FBReader – GPL e-book reader for Unix/Windows computers. Lexcycle Stanza Mobipocket Openberg Lector – cross-platform reader released under the GPL and based on Mozilla platform Reader devices SoftBook Sony Reader – the Sony Reader PRS-505 supports the EPUB file format. Intel Reader Barnes & Noble Nook Kobo eReader See also Comparison of e-book formats Open Packaging Conventions References External links Open eBook Forum Openberg Open Publication Structure (OPS) 2.0 Adobe's Sample eBook Library Article "EPUB" at the MobileRead Wiki ePub Validator - This utility allows to validate the epub file to ePub standards of 1.0.5 https://github.com/idpf/epubcheck EPUB Validator (beta) Markup languages XML-based standards