When we talk about video game, we observe that people who modified it are those who best knows its content. Thus we can consider game modifications as a way of knowledge appropriation. In this paper, we apply this model to learning games, positioning the research project in a Web 2.0 approach. If the content of a game can be learned by playing it, it can be more deeply understood by making this game evolving. The Web 2.0 is not defined by its technologies, but by the way of using it. However technologies 2.0 are developed to catalyse this participative way of use. Similarly with video games, specific tools and support are required. If they are simple enough to use, learning by game modding can be accessible to anybody without programming skills. In addition, game modding is a collaborative activity. Modders must be able to share their creations and to discuss their ideas. Thus, in our point of view, a game 2.0 environment is complete only if it allows users to play the game, to collaboratively modify it, and to share their creations. After an explanation of the game modding choice, we will present a model and a toolset for supporting such an educational activity.