• Vuze.com (formerly known as Azureus and Zudeo) - Streaming HD using a proprietary player
• Move Networks - Streaming HD using a proprietary player
• DoveTail.tv - This was in beta when I visited. It offers video downloads via peer-to-peer sharing.

ON Networks and Vimeo don't have the financial resources to create the infrastructure needed to provide streaming HD video to thousands of site visitors. Instead they turn to CDNs - content delivery networks.

CDNs have been around for about a decade. A lot has changed in that time. In 1998, online video consisted of postage-stamp size (160x120), jerky 10fps clips playing at 40kbps. Now, CDNs stream 1080i (1920x1080) HD at 10Mbps or more.

CDNs accomplish this by creating massive private networks and server farms around the world to host content and deliver it from multiple servers simultaneously. Proximity is critical to download speeds, thus the need for so many server locations.

The largest content delivery network, Akamai Technologies (Akamai is Hawaiian for smart or intelligent) has 1,000 data centers and 25,000 servers in 650 cities and 70 countries. The highly-distributed architecture means Akamai is within one network hop of 90 percent of all internet users worldwide.

The numbers are even more staggering when you consider that the throughput needed to stream HD to one million viewers simultaneously (equivalent to one Neilsen rating point) amounts to 7 terabits (trillion bits) per second.

Akamai research predicts a booming HD future. Half of the content providers polled report they already offer HD online or will offer it by Spring 2009. An additional 30 percent say they'll offer it by Spring 2010.

• Limelight Networks - Used by ON Networks
• CDNetworks - Largest CDN in Asia. Founded in South Korea to serve the huge online gaming market there.
• Bit Gravity - Used by Vimeo.com

If you're an HD video producer, getting your foot in the door of the HDTV broadcasting business is a daunting challenge. Not only are there financial barriers to entry, but HDTV programming is not yet at the point where it is catching the mass market (but it's only a matter of time before that's the case). The Consumer Electronics Association reports that only about one-third of U.S. households have HDTVs, and most of them use their widescreen TVs for games and DVDs, not television programming.

On the other hand, narrowcasting content on the internet is easy and relatively inexpensive, and you can reach a potentially huge international audience. Nielsen Online reports more than 90 percent of active U.S. internet users connect via broadband. The Information Technology and Innovation Foundation states that average download speeds are climbing worldwide. Japan and South Korea top the charts with speeds of 64Mbps and 50Mbps respectively. The average for the top 30 countries is 10Mbps with the U.S. lagging behind at 5Mbps. But even 5Mbps is more than adequate to handle streaming 720p HD.

There are minimal barriers to entry and multiple opportunities for those who want to post their HD products online.

Jeff Sengstack is a video producer, junior college computer science instructor and author of video production how-to books. He also was a TV news reporter and anchor.

• Akamai's HD promotional site
• Flash HD videos
• H.264 HD videos
• Cool HD stuff about space