Perltidy is a Perl script which indents and reformats Perl scripts. The formatting is controlled by command line parameters; the default formatting follows the suggestions in perlstyle(1).
Tidyview is a Perl/Tk application to preview the effect of perltidy options on your source code. Perltidy is extremely flexible, but the flip-side of this is that is can be difficult to check the effect of options in combination - using Tidyview can help.