DejaGnu is a framework for testing other programs. Its purpose is to
provide a single front end for all tests. Think of it as a custom library
of Tcl procedures crafted to support writing a test harness. A test
harness is the testing infrastructure that is created to support a
specific program or tool. Each program can have multiple testsuites, all
supported by a single test harness. DejaGnu is written in Expect, which in
turn uses Tcl -- Tool command language.