Institutional desktop grid systems are attractive for running distributed applications with significant computational requirements. While the rapid increasing number of users and applications running on such systems does demonstrate the potential of desktop grid and institutional desktop grid, current implementations follow the old-fashioned master-worker paradigm. Obviously, vulnerability to failures and permanent administrative monitoring are the disadvantages of client-server architectures. To bypass this, we proposed a novel system, called BonjourGrid, able to orchestrate multiple instances of institutional desktop grid middlewares, able to remove the risk of single-source bottleneck and failure, and able to guaranty the continuity of services in a distributed manner. In this paper, we use BonjourGrid protocol, which is based on publish/subscribe paradigm, to show how to adapt it to fulfill all the requirements of a decentralised job scheduler. An evaluation proves that BonjourGrid is able to manage more than 100 applications instanciated in a concurrent way on an institutional desktop grid. Analysing the execution of 100 applications with 2110 tasks during 3 hours demonstrates the potential of BonjourGrid concept and shows that, comparing to a classical desktop grid with one central master, Bonjourgrid gives an acceptable overhead that can be explained.