Apple’s iOS App Store has been a huge success since it first launched in July of 2008, with billions of downloads occurring over the past three years. So naturally, Apple decided to recycle the model for software built for its Mac OSX desktop platform, launching its own App Store in January of this year.

It’s doing well, to say the least. Apple announced on Monday over 100 million Mac apps have been downloaded since the Mac App Store debuted nearly one year ago.

“In just three years the App Store changed how people get mobile apps, and now the Mac App Store is changing the traditional PC software industry,”Apple SVP Phil Schiller said in a statement.

The Mac App Store, a feature of OS X Lion, is structured similarly to Apple’s well known iOS App Store. The iOS App Store has seen over 18 billion downloads and houses more than half a million apps. The Mac App Store is home to “thousands of apps” including things like Photoshop Elements and products from Autodesk.

The 100 million downloads figure only reflects individual app purchases. It does not include sales of OS X Lion or updates to apps purchased from the Mac App Store.

As Apple’s success with the app store model has grown, others have followed suit with their own versions. Last week Microsoft detailed its Windows Store, Microsoft’s marketplace for Windows 8 desktop and tablet applications. Although its policies and pricing scheme differs from that of Apple, it’s clear where the inspiration for the store stemmed from. Microsoft, however, boasts a much larger user base compared to Apple’s, with 500 million Windows 7 users worldwide compared to approximately 30 million Mac users.

With those sorts of numbers, it’s possible that Microsoft’s Windows Store could eventually prove to be more successful than Apple’s. But for now, Apple’s success in the app store arena is the one to beat.