In the past, I've used Slick Edit. It's Perl support is decent. Unfortunately, someone in IT decided that, when the company decided to not renew the support contract, we could no longer use Slick Edit and took down the license server. (The license is actually perpetual, so, legally, we could have kept using Slick Edit.) Now, most of the team is using the vendor-specific IDE for whichever microcontroller she/he is developing for.

I am using Geany. Syntax highlighting is good, but auto-suggest and auto-completion support for Perl is marginal.

I have tried to use PADRE (which is written in Perl), but it had some anoying (to me) issues. I intend to try it again.

I've also tried Eclipse, but the Perl plug-ins I found were marginal. Also, Eclipse doesn't auto-switch language "perspectives" when switching between files.