More than a month after the release of iOS 5, Apple has finally made its cloud music service iTunes Match available to the public. With the release of iTunes 10.5.1 (available here), Apple now offers iTunes users the ability to sync their music library across devices by "matching" each song with a high quality version stored on Apple's servers. Any other songs can be uploaded.

The service is an extension of iCloud, the cross-device content syncing feature rolled out in iOS 5. That feature lets users sync contacts, calendars, mail, apps and other data between iPads, iPhones, iPods and Mac computers. For an additional $25 per year, they can now include their entire music collection in Apple's cloud.

The launch has not been without its issues. The feature, which was delayed by several weeks for undisclosed reasons, was already unavailable shortly after its introduction today, despite the fact that Apple hadn't even yet made the update available through iTunes itself. Many users who rushed to activate iTunes Match were met with a message reading, "Due to overwhelming demand, iTunes Match is not accepting new subscriptions at this time. Please check back in an hour."

iTunes Match marks a significant step for Apple toward becoming a cloud-based repository for users' files and content. Its a noteworthy shift for a company whose success has largely been built on the sale of hardware, from laptops and desktops and tablets and smartphones.

Apple joins both Google and Amazon in this space, as all three tech giants now offer a way for consumers to store their music "in the cloud" and play it back on multiple devices.

Google Music, which is now in beta and reportedly launches very soon, takes a somewhat different approach from what Apple is doing with iTunes Match. Instead of "matching" tracks on Google's servers, the desktop client allows users to upload their entire library, a process that can take hours or even days. Those files can than be streamed from the desktop or Android-powered devices. The tracks on iTunes Match are not available for streaming, but rather need to be downloaded to each device.