The interpreter is the "engine" that executes scripts.
Download Strawberry Perl or ActiveState's ActivePerl.
Development software:
EDIT (MS-DOS), Notepad (Windows), E (OS/2), or any other ASCII editor will do.
Basically, a Perl script is just an ASCII text file with a ".pl" extension, containing the Perl code.
A more "advanced" editor or IDEdoes help make scripting a lot easier.