Spaces for critic are the places where communities of amateurs are formed, in concentric waves. Those spaces for cooperative work can be either restricted to researchers, or open to both researchers, amateurs and other publics. The critical spaces we are concerned with are defined by their access to critical resources and featured contents, the critical material around the exhibition of Centre Pompidou and the tools developed at IRI.The Amateur is so on a website for collaborative writing and annotation built around Lignes de temps which aims at the constitutions of communities of amateurs by supplying the public with featured contents and collaborative tools required for a critical exploration of topics and events. This platform is currently driving two editorial projects : the collaborative annotation website fed by the audio-guides and cellphones around the exhibition Traces du sacré and the archives of the New Industrial World Forum. This environment enables people to browse through the critical contents proposed by an editorial team and associated guests, but also by all the members of the website (the amateurs). This website emphasizes its cooperative dimension through the possibility of multiple « signatures » and through threads of discussion members can contribute to the site and debate around the commentaries raised by different topics, published via the appropriate cooperative technologies for a dynamic use of knowledge.