A challenge is an event where the organisers propose a set of tasks (Information Extraction, Question-Response, Translation, etc.) and the reference data associated with these tasks. During the challenge, several teams work on these data and implement methods for solving the proposed tasks, then simultaneously submit their predictions in the form of a submission. The organisers evaluate and rank the submissions using appropriate metrics. The challenge ends with a workshop where the participants present their methods and the organisers summarise the submissions.