Wikimedia Commons has been converted into a global repository for the documentation of cultural heritage, as well as the development of projects for the release of digitized material by memory institutions. These materials can be used, modified and distributed freely, facilitating cultural access and enjoyment, scientific research, and cultural creation through the reuse of the contents. This paper discusses the notion and characteristics of OpenGLAM and GLAM wiki projects, the activities that are carried out on Wikimedia Commons, the characteristics and problematic of the treatment of digitalized materials.