Padre is a cross-platform, open-source, free, IDE for Perl, written in Perl, and which is under active development. It's probably the most recommended for most people who don't have a previous preference.

Padre, an IDE for Perl written in Perl.

Komodo Edit is a cross-platform, costless, open-source, editor for Perl, and other dynamic languages by ActiveState. Komodo IDE is a commercially-enhanced version of it which is not open-source and costs money.

EPIC is a set of plugins for the Eclipse Java-based IDE that allows one to edit and manage Perl projects. Eclipse is cross-platform, free and open-source, and so is EPIC.

Epic, a Perl Editor and IDE based on Eclipse.

A plugin that adds Perl 5 support for IntelliJ IDEA and other JetBrains products.

Vim is a popular open-source, cross-platform, and free editor, with good support for editing Perl code. the Perl 5 Wiki page about Vim contains more information.

By default Vim behaves very much like the ubiquitous UNIX editor vi, which may seem foreign to people used to the conventions of modern desktop environments. However, using mswin.vim it can behave much more like Windows-based editors.

Vim, a sophisticated cross-platform text-editor.

TextMate is a commercial (but now open source under the GPL version 3) programmers' text editor that has become popular on Mac OS X, and E Text Editor is a commercial version of it for Windows, with source available for compiling on Linux and other systems.

These are other lists of prominent or notable IDEs - not all of them are Perl-oriented.

• Shlomi Fish’s List of Text Editors and IDEs.

• The English Wikipedia’s Text Editors category and their Comparison of text editors.

• The Text Editors Wiki.

• Rick Moen’s “IDEs for Linux” page

Perl::Critic is a Perl module (and a free web-service) that analyses one's Perl code and warns about possible bad practices that should be fixed.

perltidy

perltidy is an auto-formatter for Perl code, that can keep its style consistent. It supports many different styles and style parameters. Perltidy has a frontend called tidyview that allows one to visually customise the style and view the results.