DejaGnu is a framework for testing other programs. Its purpose is to
provide a single front-end for all tests. Beyond this, DejaGnu offers
several advantages for testing:

1. The flexibility and consistency of the DejaGnu framework make it
easy to write tests for any program.

1. DejaGnu provides a layer of abstraction that allows you to write
tests that are portable to any host or target where a program
must be tested. For instance, a test for GDB can run (from any
Unix-based host) on any target architecture that DejaGnu
supports.

1. All tests have the same output format. This makes it easy to
integrate testing into other software development processes.
DejaGnu's output is designed to be parsed by other filtering
scripts and it is also human-readable.

DejaGnu is written in expect, which in turn uses "Tcl"--Tool command
language.

Running tests requires two things: the testing framework and the test
suites themselves.