International audienceBased on a field survey conducted in France in 2017, this article identifies different forms of open datareuse and analyses the processing data chains on which they are relied. By analysing the chains and the tools usedby three categories of professional reusers (developers, data scientists and data journalists), the authors discuss theirlinks with the value creation chain. Professional practices and expectations are also discussed in terms of valuegenerated by data, of economic model (informational brokerage) but also of innovative service creation. This articleresults partially of the research ANR OpenSensingCity.A partir d'une enquête de terrain menée en France en 2017, cet article identifie différentes formes de ré...