Both Tcl and Node.JS are built around the concept of an event loop. The preffered way to do IO in both languages is to express your network application as a FSM

Both Tcl and Node.JS are built around the concept of an event loop. The preffered way to do IO in both languages is to express your network application as a FSM with callbacks on state transitions. Of course event driven IO is not in any way "owned" by either languages, what I mean is that they both encourage an event-driven IO model. Am I making myself clear?