1. A program that "talks" to other programs. Expect is a program that "talks" to other interactive programs according to a script. Following the script, Expect knows what can be expected from a program and what the correct response should be. 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. From Debian 3.0r0 APT

2. Expect is a tcl extension for automating interactive applications suchas telnet, ftp, passwd, fsck, rlogin, tip, etc. Expect is also useful for testing the named applications. Expect makes it easy for a scriptto control another program and interact with it. Install the expect package if you'd like to develop scripts which interactwith interactive applications. You'll also need to install the tcl package. From Mandrake 9.0 RPM