Not really, they're more functional, they have textual input and output, and can be chained together, but they don't really trade meaningful messages back and f

Not really, they're more functional, they have textual input and output, and can be chained together, but they don't really trade meaningful messages back and forth. Processes can be thought of as objects, and signals as messages, but the set is not extensible while OO allows the developer to define the messages.