Microsoft on Tuesday began selling its second generation Zune portable media devices along with a compatible suite of software, online services, and accessories. Unlike the first generation Zune, which arrived in the US in late 2006, this version seems uniquely equipped to compete with market leader Apple. Indeed, some of what Microsoft is now offering with the Zune, particularly its innovative and attractive PC software, far outstrips anything Apple offers with iTunes and the iPod.

"Zune brings music discovery and acquisition into one simple, end-to-end solution," says Microsoft corporate vice president J Allard. "The addition of unique customization options puts the originality back into portable entertainment."

The second generation Zune devices include two flash RAM-based players, the Zune 4 and Zune 8, which feature 4 GB and 8 GB of storage space, respectively, as well as the Zune 80, which includes an 80 GB hard drive. These devices will be sold alongside the existing Zune unit, renamed the Zune 30, which can be updated to most of the new Zune software features via a PC-based update. The new devices support unique functionality like a touch-sensitive, scrollable navigational pad and wireless sync.

The Zune PC software is quite impressive, losing the shackles of the Windows Media Player 11 application it was previously based on. The new version was created from scratch by the Zune team, and it's a beautiful looking media player, even for those who don't own Zune devices. However, as a 1.0 product, it's missing some basic features like smart playlist creation and simple album art updating.

Microsoft has also augmented the Zune with two online services. The first, the Zune Marketplace, is an update of the online store Microsoft debuted last year that now integrates nicely with the Zune PC software and offers over 1 million protection-free MP3 tracks. The second is called the Zune Social, and it allows Zune listeners to share music with others in a manner similar to that used by gamers in Xbox Live.

What's most intriguing about the second generation Zune initiative is that it appears that Microsoft has finally come up with a set of devices, software and services that can take on Apple. That certainly wasn't true of the first generation, which languished in the market, achieving just 10 percent market share in the US.

I'll be covering the new Zune all week on the SuperSite for Windows. Today, my Zune software review, Zune screenshot gallery, and Zune 4/8 photo gallery are available.