Whenever Apple unveils a new version of one of their operating systems – iOS or OS X – they tend to include at least a few new, interesting features. Unfortunately, though, these new goodies sometimes have unpleasant side effects for certain segments of the developer community. It’s not at all uncommon for iOS or OS X to introduce a feature that makes an existing third party app (or jailbreak tweak) obsolete. Whenever Apple introduces a new feature, it’s always interesting to look at where they got the idea, and which apps this new feature might kill off.

Growl for OS X is an excellent example. For years Growl has provided OS X users something that Apple did not see fit to include: a convenient, centralized clearinghouse for system and app notifications. In fact, many Mac users will tell you that Growl is one of the first things they install on any new Mac. When Apple announced in February that Notification Center was coming to OS X Mountain Lion, though, there were those who feared that that might be the end of the line for Growl. After all, Notification Center exists to do exactly what Growl has been doing for all this time. Why would you need both?

Well, it seems that Growl may have found the answer. In a blog post today, Growl CEO Chris Forsythe discussed the future of Growl in the context of Mountain Lion’s notification system. The plan, he says, is not to set Growl up as a competitor to Notification Center, but rather to allow Growl to compliment and augment Notification Center. The goal is to “help developers transition from Growl to Notification Center on their terms.”

To do that, Growl 2.0 will make a simple modification to a feature introduced with Growl 1.3. This feature, called Mist, is a modification to the Growl framework used by developers to integrate Growl support into their apps. Essentially, if Growl is not running, Mist generates a notification anyway. To accommodate Notification Center, Mist will be updated to include a single line of code that directs that notification through the Notification Center. That’s it. Here’s what Forsythe has to say about it:

The benefit of this is that you do not need to rewrite your code, you’ll simply drop in an updated Growl.framework, update the XPC if you use that, and then you’re done. You now support Notification Center. If Growl is running, then Growl is used. The notification experience is pretty straight forward, users who want Growl are happy, users who just want NC are happy, etc etc.

All in all, it looks like a win-win. In fact, it makes Growl extremely useful for developers whose apps are not in the Mac App Store. You see, Mountain Lion’s Notification Center only supports App Store apps. If you download from another source (something Apple would really rather you didn’t do), then the app can’t send notifications to Notification Center. With Growl, you can still see notifications from your non-App Store apps.

While Notification Center is certainly a cause for concern for Growl, the fact that OS X is not the same kind of walled garden ecosystem as iOS means that there will always be room for apps like Growl.

Growl 1.3 is currently available for $1.99 in the Mac App Store.