This is an interactive shell for Perl, commonly known as a REPL -
Read, Evaluate, Print, Loop. The shell provides for rapid development
or testing of code without the need to create a temporary source code
file.

Through a plugin system, many features are available on demand. You
can also tailor the environment through the use of profiles and run
control files, for example to pre-load certain Perl modules when
working on a particular project.

WWW: http://search.cpan.org/dist/Devel-REPL/