Computable Document Format
Computable Document Format (CDF) is a dynamic document format associated with the Mathematica mathematics software. It is a text-based format.
CDF is publicly documented, but it is pretty much impossible to properly render it without using components of the proprietary Mathematica software.
- Wolfram Language & System Documentation Center - Allegedly, CDF is documented here.
- Wolfram Demonstrations Project → * → "Download Demonstration as CDF"