Reactive concurrent programming revisited
  In this note we revisit the so-called reactive programming style, which evolves from the synchronous programming model of the Esterel language by weakening the assumption that the absence of an event can be detected instantaneously. We review some research directions that have been explored since the emergence of the reactive model ten years ago. We shall also outline some questions that remain to be investigated. 
Roberto Amadio (PPS), Gerard Boudol, Ilaria Castellani, Frederic   Boussinot