In a posting from Netflix blogger Brent, the company said it's past the first stage of its beta testing for the player software, and is inviting everyone to join in. However, Netflix warned that there still might be some glitches.

"We are logging all errors, but if you run into problems, you can help out by posting details here in the blog comments," Brent wrote. "Not all movies are available to watch with Silverlight. You may notice errors or lower-than-normal quality when watching certain titles. Our new player works on PCs and Intel -based Macs. Windows users should be aware that if you opt in, you will need to use Silverlight on all the machines you use to watch instantly."

The new software will give Mac users access to Netflix's library of approximately 12,000 streaming videos; by contrast, DVD renters can select from among 100,000 titles.

Important Market

Although the percentage of Mac users is small compared to Windows users, it's still an important market for Netflix, said Michael Gartenberg, vice president of mobile strategy at Jupitermedia.

"It's important for a few reasons," Gartenberg said. "While Apple's market share is still much smaller than Microsoft 's, it has shown and continues to show the type of growth and momentum that developers are interested in. That's why we're seeing the effort to get the Netflix player on the Mac. Macintosh customers represent a key demographic that Netflix wants to serve, so getting on that platform was an important move."

No Flash

In developing its streaming video player, Netflix elected to use Microsoft's Silverlight digital media-delivery system instead of Silverlight's chief rival, Adobe Flash. The software contains built-in digital-rights management as well as more advanced timeline navigation and faster downloads.

As Brent noted, Silverlight is available only for Intel-based Macs, which Netflix says is about three-quarters of its subscribers who own Apple computers. Both Windows and Mac users will need to download and install the latest version of Silverlight (and have a Netflix account) in order to test the new player.

One thing that the Silverlight software does not do is allow users to transfer downloaded videos from a PC to other devices, such as a portable video player (like the iPhone) or a television. That may leave Netflix at least temporarily at a competitive disadvantage with Apple's iTunes Store, which allows renters and purchasers to watch a downloaded movie on a computer, an iPod or Apple TV.

However, Gartenberg said he didn't think the lack of portability would be a huge problem for Netflix.

"The point of the Netflix service ," he said, "is that it supports many platforms, including their own hardware box codeveloped with Roku, PCs, the XBox 360 and [just] announced last week, TiVo."