Visible Light Communication (VLC) has emerged in the last few years as a promising technology not only for high-speed communication but also for serving a new generation of Internet of Things (IoT) devices that may leverage the pervasive lighting infrastructures. But, what is VLC and what are its key design aspects? In this talk, we will first answer these questions, and we will then review our journey on lowering the entrance barriers for performing research with VLC, introducing the open-source OpenVLC platform, and providing exemplary case studies on how we have applied it in our research group. In the last part of the talk, we will show how VLC can become a pivotal technology for sustainable 6G networks, jointly delivering lighting and networked communication to battery-free IoT devices, while being integrated with radio-frequency solutions, and how we are using it in the context of greenhouse and vertical farms applications.