Google on Tuesday took the wraps off a new weapon that ups the ante in the company's growing arms race with rival Microsoft for control of the Internet search marketplace.

In a blog post that caught most of the tech world off guard, Google engineers revealed that the company has been working for months on a "next generation" search architecture dubbed Caffeine.

In their post, Sitaram Iyer and Matt Cutts said Caffeine promises to "push the envelope on size, indexing speed, accuracy, comprehensiveness and other dimensions" of Internet search.

The engineers provided few technical details about Caffeine—not surprising given that search technology is Google's answer to McDonald's "Special Sauce" or KFC's Original Recipe—but noted that the platform would function "under the hood" of Google's existing search pages.

"Which means that most users won't notice a difference in search results," Iyer and Cutts wrote.

Google is inviting Web developers to test out a new page powered by Caffeine and provide input. "Right now we only want feedback on the difference between Google's current search results and our new system," the engineers said, noting they're particularly interested in differences between Caffeine's site rankings and those yielded by Google's existing search page.

Though little is known about Caffeine's inner workings, its launch comes amid an all out effort by Microsoft to dramatically improve its standing in the search market—where it's currently a distant third to Google.

Microsoft last month reached a partnership with number two player Yahoo, under which it will extend its new Bing search engine to all of Yahoo's Web properties. Microsoft also gained license to Yahoo's search patents and licenses, which represent technology Yahoo spent millions of dollars to develop.

Yahoo will keep most of the revenue generated by the deal, but the arrangement delivers unprecedented scope and scale for Microsoft's search engine.

Microsoft launched Bing in June, positioning it as a so-called "decision engine" that delivers more than just page results. Redmond claims Bing cuts through search clutter by yielding information—such as hotel room vacancies and prices—upon which consumers can immediately act.

Google did not state when it plans for formally launch its Caffeine architecture.

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