Particle-accelerating colliding-wind binaries: from the study of a few objects to a science case study

The study of massive stars, and in particular of colliding-wind binaries, revealed the capability of some of them to accelerate particles up to relativistic energies. Since the 1980's, what appeared at first sight to be an anomaly in their observational properties turns out to be the signature of important physical processes at work in a large number of objects. In this contribution, I summarize the current census of information relevant to the catalogue of Particle-Accelerating Colliding-Wind Binaries (PACWBs) that constitute a particular class of objects likely to contribute to the production of low energy Galactic cosmic-rays. On the basis of this census of information, some prospects for future observational strategies are discussed.