I am working on an example: from twisted.internet.app import Application from twisted.internet.protocol import Protocol, Factory class Fibonacci(Protocol): """Serve a sequence of Fibonacci numbers to all requesters""" def dataReceived(self, data): self.factory.new = self.factory.a + self.factory.b self.transport.write('%d' % self.factory.new) self.factory.a = self.factory.b self.factory.b = self.factory.new def main(): import fib_server # Use script as namespace f = Factory() f.protocol = fib_server.Fibonacci f.a, f.b = 1, 1 application = Application("Fibonacci") application.listenTCP(8888, f) application.save() if'__main__' == __name__: main() I have questions as the following: 1. Is application.save( ) that make Fibonacci.tap file? 2. testing on "twistd -f Fibonacci.tap" got message "Failed to load application: No module named fib_server".Can we use script as namesp? -- Steve Han