Editors

1.  syntax coloring
2.  realtime syntax checking
3.  version control integration
4.  code-assist editor to provide a list of method when you type in an object reference (for example)
5.  excellent refractoring support
6.  a tree view of source files and resources
7.  support for creating and running unit test
8.  language specific help (display perldoc)
9.  realtime display of debugging result
10. automatic code reformating
11. seamless handling of multiple languages
12. automated build and test support

Vim, Protoeditor, Eclipse EPIC
http://www.softpanorama.org/Scripting/Perlorama/perl_programming_environment.shtml
http://www.perl.com/lpt/a/955