Definition(en): Microsoft PowerPoint Presentation is a proprietary binary file format developed by Microsoft Corporation used to store presentation files created in the Microsoft PowerPoint presentation system. This record describes version 2 of .ppt file format for Macintosh, released in May 1998. Versions up to version 4 of Microsoft PowerPoint use .ppt as extension, however they are not compatible with each other. Microsoft made backwards compatibility an optional add-on after Office 2003 and appears to have removed it altogether in Office 2010.