A four-year-old startup called Vusion today comes out of stealth mode, launching a streaming video platform competitive with Move Networks. I was blown away by a demo over my dinky home Internet connection — the service is responsive, instant, and incredibly high quality (see showcase).

Vusion said it requires broadband download speeds of 1.5 Mbps for 480p videos and 2.5 Mbps for 720p videos, making it fairly widely accessible. Akamai, by contrast, told us last year it expects only 10 to 20 percent of end users to have good enough connections to have a good experience watching its own HD offering.

As usual for these services (other competitors include GridNetworks and Digital Fountain), end users will need to download a small piece of software to manage video delivery. On the plus side, Vusion does support Macs at launch.

The San Jose, Calif.-based company, formerly known as Jittr Networks, has been working on its technology for four years. So yes, it’s a bit slow to market, but then again this market is only exploding just now. VP Marketing Grover Righter would not detail the company’s specific improvements, saying it’s a combination of tweaks to existing solutions.

“Video is an unnatural use case for the Internet,” was his hint. “The Internet doesn’t have a clock in it. It can’t tell you it’s second one, second two, with video here, here, and here. [Our solution is] not multistream with commodity servers, and three different ones coming to you. The Internet is actually overpopulated with data. You’re putting more video on the Internet than people can actually watch.”

Righter contended Vusion’s technology is further along than Move, but admitted that Move is way ahead in terms of business development. Vusion is announcing today it has signed Island Def Jam Music Group as a customer; Move has a mess of television networks under its belt: ABC, FOX, ESPN, The CW.

Also, Vusion has raised an undisclosed amount of funding (we think it’s under $10 million), compared to the $68 million Move has hauled in. Vusion’s funding comes from BlueRun Ventures and “entertainment industry” investors, according to Righter.