But Growl's presence in the store isn't a death knell for the software as an open-source project. "Growl is definitely still open source," Forsythe told in an interview prior to Monday's release of Growl 1.3. "Currently our [software repository] is locked down but once 1.3 is out, we'll open it up." Despite the end product only being available through the Mac App Store, independent users will still be able to download and compile the source code from Growl's site, as per the terms of Growl's BSD license.

Of course, its appearance in the Mac App Store isn't the only change in Growl 1.3. Like iOS notifications, Growl gets a makeover; it even has its own version of iOS 5's Notification Center in the new Rollup feature. "[Rollup] will display messages that came in while you were away," Forsythe said. "Everyone who uses Growl will love this in my opinion."

Rollup also paved the way for another feature: a History log, much like what you'd find in many browsers. By visiting Growl's History pane, one can revisit notifications that happened five minutes or five days ago, complete with the ability to search if they're looking for something in particular. These can be especially handy for folks who have a lot of notifications, helping solve the problem of seeing a pop-up out of the corner of your eye, only to have it vanish forever.