What does XPC stand for?

Expect

Expect, an extension to the Tcl scripting language written by Don Libes, is a program to automate interactions with programs that expose a text terminal interface. Expect was originally written in 1990 for Unix systems, but is now also available for Microsoft Windows and other systems. It is used to automate control of interactive applications such as telnet, ftp, passwd, fsck, rlogin, tip, ssh, and others.