The International Baccalaureate (IB) Curriculum and Assessment center based in Cardiff, Wales, UK.
This is the administrative organization in charge of managing the IB final examinations, assessing these and any other externally assessed work within the program, and evaluating the various subject syllabi.
The internationally comprised body of examiners also determine the final grade awarded to students based on results from internally and externally criterion-based assessment. The process whereby this is done is secretive to the point where it makes NSA seem like an open source project. It is, however, commonly believed that grade boundaries are determined every six months (since the IB follows each hemisphere's respective school year) based on global quotas.
A large part of an IB student's time goes to figuring out what appeals to the examiners, and praying that their work will be assessed shortly after their assigned examiner's coffee break.