Stephen Shankland/CNET

Opera Software, an independent voice in the browser market since the 1990s, will dramatically change its strategy this year by adopting the WebKit browser engine used by Safari and Chrome.

The Norwegian company announced the move today and said it will show off the first fruits of the work with a WebKit-based version of its Android browser at the Mobile World Congress show in less than two weeks. But the company will move to WebKit for its desktop browser, too.

A browser engine processes the Web page instructions written in HTML, JavaScript, and CSS then renders the results on screens. The engine is increasingly important as the developer world expands from static Web pages to dynamic Web apps.

Opera's chief technology officer, Håkon Wium Lie, described the company's motives for the change in a statement:

The WebKit engine is already very good, and we aim to take part in making it even better. It supports the standards we care about, and it has the performance we need. It makes more sense to have our experts working with the open source communities to further improve WebKit and Chromium, rather than developing our own rendering engine further. Opera will contribute to the WebKit and Chromium projects, and we have already submitted our first set of patches: to improve multi-column layout.

Hints of Opera's WebKit work emerged with a mobile-browser project called ICE in January, but today's news is a much more sweeping change than just a single product. Opera said it will move gradually to the WebKit for "most of its upcoming versions of browsers for smartphones and computers." It's not immediately clear which products will continue to use Opera's in-house technology, and Opera declined to say which.

Opera has struggled to keep its fifth-place ranking in the browser usage, but it's certainly not irrelevant. The company also announced today that 300 million people use its browsers each month.

But there are difficult trends the company must face. On mobile devices, Opera Mini is a strong contender, but its popularity is chiefly on lower-end phones; iOS and Android devices come with their own WebKit-based browsers. On personal computers, Google's Chrome rose from nowhere in a few years, quickly surpassing Opera and Safari, while Microsoft by some measures has reversed declines in its share of browser usage.

Although ditching its in-house Presto browser engine raises the possibility of engineering layoffs, Opera spokeswoman Zara Lauder took an optimistic tone when asked about it.

"We have never had more people at Opera working on our products than right now, and we look forward to contributing to WebKit," Lauder said. "This change has been some time in the making, and all hands are now hard at work on making the best possible browser for our users."

She didn't specifically deny layoffs, though, and Mozilla's Tristan Nitot said today, "They have recently laid off quite a few people in their 'developer relations' program." Nitot leads developer relations for Mozilla in Europe.

Although Opera's profile is lower than that of many rivals, it's still functioning financially. During the company's third quarter of 2012, the most recent for which financial results are available, Opera reported revenue grew 40 percent to $56 million, and its profit was $6.5 million. Its revenue sources include payments from search traffic it drives to partners including Google and Yandex, its own advertising technology, and partnerships with mobile network operators.

Why WebKit

The WebKit project began as the KHTML engine used in the KDE project to supply Linux with a polished user interface and a host of software utilities, but Apple became its chief sponsor when it based OS X's WebKit on the project. WebKit got another major boost with Google's embrace.

Adobe Systems now is also contributing as it moves to recreate many of Flash Player's abilities without requiring the browser plug-in, and WebKit also is used in the browsers of BlackBerry OS and Samsung's Bada.

One notable consequence of moving to WebKit is that Opera will be able to more easily support the large and growing number of iOS devices. Apple rules prohibit browser engines besides a version of WebKit that Apple itself supplies (and incidentally, that runs slower than the version Safari on iOS itself uses). Google's Chrome for iOS uses this Apple-supplied version of WebKit, and Opera would be able to make such a move more easily if its own browser used WebKit, too.

WebKit is not a single, unified project, though. For example, Chrome and Safari differ dramatically under the covers in how they execute the JavaScript programs on Web pages. Chrome uses Google's V8 JavaScript engine, whereas Safari uses a different one called Nitro. Opera said it will use V8.

Another consequence of Opera's change is that developers could have an easier time supporting browsers. Although independent testing will still be required, Web pages likely will be easier to write and test -- especially advanced ones using newer features such as animations and "responsive" design that can handle a wide variety of screen types.

With Opera throwing in the towel on its own Presto engine technology, the bulk of the browser market will be reduced to using three primary engines: WebKit, Microsoft's Trident, and Mozilla's Gecko.

Lie also announced Opera's move on the WebKit mailing list.

"Switching from Presto to WebKit frees up resources and allows us to contribute to the WebKit platform," Lie said.

Being part of WebKit potentially gives Opera more clout in the standards world, because it can build experiments that are more easily tested and adopted by fellow WebKit members. That, in turn, makes it easier to formalize new ideas into actual standards.

Opera has begun work on first such standard through WebKit, an approach at Web page layouts that handle multiple columns of text and graphics more easily. Opera has begun submitting patches for the multicolumn layout idea.

"We have experimented with combining multicol layout with page floats and column spans; in 10 lines of CSS code one can create amazingly beautiful, scalable, and responsive paged presentations," Lie said.

Opera's move from Presto to WebKit arguably gives the company a lot more engineering breathing room, since it can share labor with other browser makers instead of pulling all its own weight. But not everybody was happy to hear the news.

"Sad day for my former team at Opera and for the Web to lose a rendering engine," tweeted Anne van Kesteren, who for years worked on standards issues at Opera.

Updated at 12:53 a.m. PT, 1:37 a.m. PT, and 8:38 a.m. PT with further details, comment from Opera, and a report of developer-relations layoffs.