the editor component of Komodo is licensed under some sort of open source license.

Not in the least, the license agreement page makes it very clear that the program is closed and proprietary. It even goes to the extent to claim "you may not provide any End User with access to the development or interactive capabilities of the Software libraries or technology, nor may you expose the base programming language(s) as a scripting language within the Works to any such End User.".

I also find the usage of such applications to be redundant and carry a huge overhead. Working with languages such as Java, or C#, that impose the programmer with tons of redundant syntax of their own, such tools are needed to keep track of everything that goes around the code (even inside a class).
For Perl, this is truly an overkill and has the added issue of forcing the IDE way of doing things on the programmer.
A good text editor would suffice, and allow to focus on the actual task, while not limiting in anyway (rather than the interface).

One known advantage of IDEs for other languages is that these usually combine the editor component with a compiler and debugger into a (pseudo-)integrated environment (hence the name), but Perl itself is already such an environment with perl and perldb.
If something fancier is needed, the debugger can be integrated with existing editors, or be called via a GUI (e.g. ptkdb).

UPDATE: I missed the OpenKomodo project which is free-software (or will be, it seems to be in very early development stage).