Workflows coordinate tasks across departments or organisations, where correct execution depends not only on control dependencies but also on the availability of shared resources. This paper presents ReAct, a resource-aware active object language for workflow modelling. In ReAct, method declarations serve as contracts: they specify alternative resource profiles in their signatures, giving methods multiple execution options when resources are limited. Methods can be invoked only once their dependency conditions are satisfied; at activation, a feasible resource profile is then selected and allocated. We encode the language in Maude and show how workflows can be executed, simulated, and verified against their declared dependencies and resource requirements.