Free and open source software (FOSS) has gone through a series of phases, from a little-noticed movement, to early industry adoption in the lower levels of the software stack, to inroads in the vertical application market, to merely table stakes in modern software development: In recent years, disruptive applications in the trendy segment of machine learning are natively born as open source. There is no doubt that in just over 20 years FOSS has radically changed the way software is designed, developed, evolved, distributed, marketed, and sold.

One could be tempted to say that since FOSS is now mainstream across all layers of software development, with even its most fierce former opponents turning into fervent adopters, it has reached its maturity phase and there is no longer a need for a specialized forum dedicated to studying it, like the one OSS has being providing for over a decade.

Nothing could be further from the truth: With the huge number of newcomers that now embrace FOSS without having contributed to its evolution, and knowing very little of its values and inner workings, it is now more essential than ever to study, understand, and explain fundamental issues related to the business models, organizational structures, decision-making processes, quality metrics, and the evolution of the free and open source software ecosystems in general.

This effort involves a variety of scientific disciplines, ranging from core computer science, to social sciences and economics, and this work must be performed in close connection with the developer communities that are reshaping our software world daily.