A program that can automate interactive applications Expect is a tool for automating interactive applications according to a script. Following the script, Expect knows what can be expected from a program and what the correct response should be. Expect is also useful for testing these same applications. And by adding Tk, you can also wrap interactive applications in X11 GUIs. An interpreted language provides branching and high-level control structures to direct the dialogue. In addition, the user can take control and interact directly when desired, afterward returning control to the script.