The WikiLab is a collaborative construction based on the WikiHouse project, that started in São Paulo, Brazil, in 2017 and is still occurring, being a continuous experience. The construction was done mostly by a team of volunteers, it mixes architecture, CNC manufacturing, collaborative planning, construction and management, ecological, technological and social research, and the whole design was done completely with free software, mostly FreeCAD. In this talk, I'll try to showcase how the use of free software had a very special impact on the project design and construction, how this reaches areas where no commercial software entered before, and how this can change the way we do architecture.