"Also, Growl remains Open Source Software. This page explains how to build Growl from source."
I'm not much of a coder, so I won't check if that is truly the v2.0 source linked in the page, but they seem to have a very clear statement that they're remaining open source.
I guess my whole point is that "open source" doesn't mean zero payment or only available online, it just means that once you obtain the software, you may work with the source code as you please.
With that, I wish you fine people goodnight, and happy writing!
Dustin Wheeler
Sent from my iPad