The Open Document Format (ODF) become an OASIS standard in 2005 and an ISO/IEC standard in 2006. Today, is the only true open standard for document formats available on the market, and the only one protecting users from proprietary lock in and ensuring a full control over contents. The presentation provides an overview over ODF features and explains why ODF should be used versus Microsoft OOXML (DOCX, XLSX and PPTX).