This document is a habilitation à diriger des recherches (HDR) thesis. It is organized in two parts: The first part presents a reflection on my work and the state of the Natural Language Processingcommunity ; The second part is an overview of my activity, including a detailed CV, a summary of the work of the PhD students I contributed to advising, and a list of my personal publications.Self-citations are postfixed with and listed in Chapter 9, while external references are listed in the bibliography at the end of the document. Each contribution chapter ends with a section listing PhDstudent work related to that chapter.