Today, the digital platform exists for almost all areas of life. The platform is thereby always the intermediary between supplier and customer. From a socio-ecological perspective, this "platformisation" must be seen critically. The social perspective shows an increasing dependence on a few platform companies and a restriction of the negotiating power of external traders and service providers. For the ecological perspective, initial positive expectations of a more efficient use of resources are disappointed in practice. The on-demand culture and the placement of personalised online advertisement lead to additive consumption and promote additional resource use. There are two counter-movements to this development: on the one hand, platform cooperativism, which pursues the goal of placing social-ecological values at the forefront of platforms. On the other hand, the Free/Libre and Open Source Software (FLOSS) movement exists, which focuses on forms of ownership, transparency and rights of use of software. The two movements share the goal of bringing the platform or its software into joint ownership. Even if the merging of both movements could offer special potentials for social-ecological platformisation, the movements often still act separately from each other. The article highlights possible synergies between the two movements and asks how a social-ecological platform could be created.