1. Amazon.com
'Excellent' rating: 50.4% Reuters

Amazon today launched a Mac application store, pitting the company against Apple's own five-month-old Mac App Store.

The company launched a new subsection of its online retail store, dubbed Mac Software Downloads, this Thursday.

The company has offered software downloads for the Apple computers before, but today's move marks the first time the company grouped the apps together into a store.

Amazon's Mac download store even has some software that Apple's doesn't, such as Microsoft's Office suite.

Amazon's app store supports Mac OS X 10.5, aka Leopard and newer; Apple's works only on Macs running the newer OS X 10.6.

This isn't the first time the retailer encroached into Apple's territory.

The company launched its own AppStore recently that serves as a marketplace for Android apps. Apple sued Amazon, claiming that they own the rights to the words AppStore.

Amazon also recently launched a digital music locker service, a cloud based utility that allows users to store their music for playback anywhere there is Internet.

It is widely believed that Apple is also prepping a similar service to compliment its new iPhone 5 and upcoming iOS.

As part of the store launch, Amazon is offering buyers a $5 discount on any Mac game or software purchase through June 1, 2011.