WASHINGTON -- Google rules the roost when it comes to Internet search and has easily brushed aside efforts by Yahoo!, Microsoft and others to knock it off its perch.

While not a traditional Web search engine, a new challenger is emerging on Friday -- WolframAlpha, named after the man behind the venture, British-born scientist and inventor Stephen Wolfram.

Wolfram, who earned a PhD in theoretical physics from Caltech at the age of 20, is careful not to call his latest invention a search engine, describing it instead as a "computational knowledge engine."

Unlike Google, which takes a query and uses algorithms to return a series of links to relevant websites, WolframAlpha.com takes a query and crunches through its databases to return answers.

"The basic idea of WolframAlpha is very simple," Wolfram said in an online presentation of his venture, which is scheduled to go live for a test run at 8:00 pm Friday (0000 GMT Saturday).

"You type your input, your question and WolframAlpha produces a result."

Danny Sullivan, editor-in-chief of SearchEngineLand.com, said in a telephone interview with AFP that WolframAlpha is a "really interesting tool."

"I try to describe it as a 'fact search engine' to help people understand the degree that it's different from Google," he said. "Google tends to point to stuff while (WolframAlpha) actually have some answers."

He said WolframAlpha was not presenting itself as a rival to Google "although they want to capture the general search audience too.

"They're saying they're not trying to wipe out Google but they feel they do the kinds of searches that Google doesn't handle," Sullivan said.

"If you're trying to get facts this might be a handy kind of encyclopedia for you.

However, Sullivan said the Massachusetts-based WolframAlpha "has some issues." "It can be kind of finicky," he said.

"It doesn't have answers to everything that you might try," Sullivan said. "So you tend to get sort of a dissatisfied feeling if you've done your search and it comes up with nothing for you."

Another problem with WolframAlpha may revolve around sourcing, he said.

"Anytime you do a search they'll tell you where the data has come from and where they're pulling it from," he said. "But, you know, sources from all sorts of places can be wrong.

"So there will still be that issue where some people may feel like 'Hmm ... I don't know if I want to trust this,' in the same way that they don't want to trust Wikipedia sometimes," he said.

Wolfram, in his presentation, said WolframAlpha is a "long-term project which in many ways is just getting started.

"We're trying to take as much of the world's knowledge as possible and make it computable," he said. "So that anyone, anywhere can just go to the Web and use all that knowledge to compute answers to their specific questions."

Sullivan said he believed WolframAlpha's was the most ambitious search project in recent years outside of Microsoft's unsuccessful efforts to steal market share from Google.

"It's a fairly large project they've put together," he said. "They've got like 150 people."

Google dominates online search in the United States with a more than 64 percent share of the market followed by Yahoo! with 20 percent and Microsoft with less than 10 percent, according to industry tracking firms.

Sullivan said that as impressive as WolframAlpha may be, Google just might still be one step ahead.

He noted that the Mountain View, California, Web giant earlier this week unveiled a laboratory project called Google Squared which it plans to release later this month.

"What it does is actually trying to go beyond what Wolfram is doing," he said. "Wolfram is gathering information that's been all nicely and neatly put into databases and spreadsheets and everything.

"Google Squared is trying to find information from across the Web and automatically build those kind of spreadsheets for you."