If you are an Emacs user, you might know or even use cperl-mode. I am using it, more or less since my first days with Perl. Back then, newsgroups were a thing, and Ilya Zakharevich recommended it occasionally. In older times cperl-mode was shipped with Perl, today it is part of Emacs.
If you use cperl-mode, you might also have had a look at the code and noticed that it hasn't seen much love in the last decade or so. Perl, on the other hand, evolves. Version 5.32, for example, brings a new infix operator, and some future version might bring Cor. Wouldn't it be nice if cperl-mode understood these new keywords?
I'm on my way to get familiar with emacs-lisp, ERT, and other stuff to see what I can do. Ideas, contributions, comments, bug requests and criticism is welcome - There's a GitHub repository to get started.