How is OpenAD open?

The AD transformation engine (xaifBooster) provides two interfaces.
  1. XAIF: the representation of the numerical kernel that is relevant to AD. Any language specific front end capable of representing a code in XAIF can provide input to the AD transformation engine. Depending on the use algorithm the front end must be able to parse the resulting XAIF output and translate it into the original programming language. Which XAIF extensions used in output are specific to the algorithm producing it.he
  2. xaifBooster is coded in C++ following a design that separates the transformation algorithms from the underlying class structure that represents all the information supplied via XAIF. The goal of this design is to allow an relatively easy reuse and extension of the existing algorithms. This helps our development and allows outsiders to implement their own algorithms with a comparatively small coding  effort.