Known as "ISO/IEC 29500, Third edition, 2012-09-01"
ISO :
- Part 1: Fundamentals and Markup Language Reference
- Part 2: Open Packaging Conventions
- Part 3: Markup Compatibility and Extensibility
- Part 4: Transitional Migration Features
MSDN :
- PowerPoint Viewer
- DocumentFormat.OpenXml.Presentation Namespace on MSDN
- Open XML SDK 2.5 with Validator