You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an alternative browser.
pptx
Office Open XML (also informally known as OOXML) is a zipped, XML-based file format developed by Microsoft for representing spreadsheets, charts, presentations and word processing documents. Ecma International standardized the initial version as ECMA-376. ISO and IEC standardized later versions as ISO/IEC 29500.
Microsoft Office 2010 provides read support for ECMA-376, full support for ISO/IEC 29500 Transitional, and read support for ISO/IEC 29500 Strict. Microsoft Office 2013 and later fully support ISO/IEC 29500 Strict, but do not use it as the default file format because of backwards compatibility concerns.