About OpenXML
OpenXML is also known as OOXML and it fully XML-based format for office documents, including word processing documents, spreadsheets, presentations, as well as charts, diagrams, shapes, and other graphical material. The specification was developed by Microsoft and adopted by ECMA International. In previous order binary formats likes.doc, xls, and .ppt continue to be supported by Microsoft but OpenXML is now the default format of all Microsoft Office documents likes .docx, .xlsx, and .pptx. The specification OpenXML schemas and constraints in written form and Any conforming document must conform to XML schemas, and be in UTF-8 or UTF-16 encoding. It is also used in the word processing documents, SpreadsheetML for spreadsheet documents, and PresentationML for presentation documents. It also includes some supporting markup languages, most importantly DrawingML for drawings, shapes and charts.