Back in 1984, the original Mac could only run a single program at a time. But we've come a long way in the last quarter century and these days our computers can do more things at once than we can -- or often want to -- count.

Growl is a notification service that helps you keep track of all those things. It manages those events and keeps you in the loop. An application tells Growl that something happened and in turn, it will present that information to you in a method of your choosing. The default notification (and likely most popular) is with little translucent boxes that appear in the upper right-hand corner that fade out after several seconds with an icon and some text.

Growl isn't part of the OS; it's third-party software. Many third-party programs use Growl, and sometimes a program will install Growl without making it obvious to the user -- including Adobe with Creative Suite 5. And that has created a bit of stir with the Growl developers.

The strength of Mac OS X is in the software on the platform: some good, some bad, some expensive, others free. The question is, how does a good, free piece of software that is even copied on other platforms, end up with angry users?

I recently talked to two of the people behind Growl and the issue of its installation. (Instructions for uninstalling Growl are available on the Web.)

Derik DeLong: Who are both of you?

Cristopher Forsythe: I'm Chris, the the Project Lead for Growl.

Peter Hosey: I'm Peter Hosey, lead developer on the Growl project.

CF: Essentially we both have final say the direction of Growl, with Peter focusing on developery things, and Chris focusing on the other stuff.

Peter is also a Developer on Adium, and has spent a lot of time on his blog talking about programming and providing applications to help people with all sorts of things.

Myself, I was previously the Project Manager for Adium, and I'm the Project Manager for Perian. I also have the most awesome 6-month-old on the planet.

DD:For those that don't know what Growl is, what is it? What does it do for a user?

PH: It's a free, open-source notifications system for Mac OS X.

It enables applications to send the user notifications, which, by default, Growl displays as little rounded-rectangle bubbles that fade in and out on the screen. Growl also enables the user to configure how it displays the notification; options include alternate styles of bubble, reading the notification aloud via text-to-speech, and even sending SMS messages or (with a third-party plug-in for Growl called Prowl) iOS push notifications.

CF: Growl is this cool notification thing for OS X that we've been working on for about seven years now. Say you have a few applications open on your Mac, and you receive an e-mail. Without having to go over to your mail program, you can get a summary of what's going on.

What I use Growl for is very limited, actually. In Adium, I like seeing notifications from people if Adium isn't the directly used/front/active app. I like knowing when uploads complete in Cyberduck, and then a few random things in iTunes.

Other people love things like our HardwareGrowler, which tells you when some hardware is plugged in and unplugged, or when they get onto a new wireless network. And of course people love GrowlMail.