In the last two decades, the use of OpenFOAM as a multi-physics library for nuclear applications has grown from a sporadic use for exploratory studies to a widespread application for the analysis of innovative reactor concepts and highly complex problems. This review paper provides an overview of the past and current development efforts in the field and summarizes some of the lessons learned during 10 years of R&D activities participated by the authors. The objective is to provide readers with an understanding of the benefits and challenges of this approach, thus facilitating an informed decision about its potential adoption for future studies.