Jean-Lou Dupont developed a Python implementation of the actor model design pattern called mswitch that facilitates message passing between loosely coupled actors. mswitch acts as an anonymous message bus that connects actors, allowing first-time messages to be broadcast to all interested actors and subsequent messages to only be delivered to explicitly interested actors. Actors connect to mswitch and can send and receive messages, with mswitch handling the routing. This implementation supports both inter-process and intra-process communication between distributed actors.