Abstract: A distributed computing system having a distributed protocol stack. In a system including one or more general purpose computers or other application processors for running applications, the distributed protocol stack off-loads communication or other I/O processing from the application processor to dedicated I/O processors using a STREAMS environment thereby enhancing the performance/capacity of the system. The distributed protocol stack is formed of a STREAMS stack top and a stack bottom so that together the stack top and stack bottom comprise a full stack functionally equivalent to a non-distributed stack running on an application processor. Both the application processors and the I/O processors together appear to execute the full protocol stack, but the application processor only executes the stack top while the I/O processor only executes the stack bottom.