Google has released new software designed to let Web developers write more powerful programs that can work directly with an operating system, rather than having to be run through a browser.

Called Native Client, the software was released under an open-source software license by Google engineers on Monday. It's still in an early stage of development, but Google says it could eventually help Web developers create Web programs that would run more quickly and feel more like real desktop applications.

Developers could use Native Client to speed up a photo-sharing Web site, for example, so that users could touch up photos without ever leaving the site, Google spokesman Brad Chen wrote on a company blog. "Modern PCs can execute billions of instructions per second, but today's web applications can access only a small fraction of this computational power," he said.

Google doesn't expect the software to be widely used just yet. "Native Client is a research technology so the goal of this release is to expose it to the research, security and open source communities for their feedback and contributions," a Google spokeswoman said via e-mail.

Native Client looks similar to Microsoft's ActiveX technology but will run on Linux and the Mac OS as well as Windows, Web experts said Monday. It also bears a resemblance to an Adobe technology called Alchemy.

Developers create their code using a version of the GNU C Compiler, so that desktop applications can be compiled to run on the user's PC using a special browser plugin.

"Google is clearly reaching for ways to take more control over the desktop, the Web browser and user content," said Robert Hansen, CEO of security consultancy SecTheory, via instant message. "Native Client appears to be another way to reach into people's computers and use as many resources as possible. It's not a matter of whether it can be done. It's a question of if it should be done. We haven't even solved yesterday's problems yet, let alone another ActiveX clone."

Native Client is not intended to replace any existing technology, Google said. "We believe developers can use this technology alongside others to create applications that provide a richer, more dynamic experience than ever before," the Google spokeswoman said.

The software does not yet work with Microsoft's Internet Explorer, but runs on the Google Chrome, Firefox, Safari and Opera browsers. The developers hope to support Internet Explorer eventually, the spokeswoman said.

To keep Native Client secure, Google has built what it calls an "inner-sandbox" that will analyze code for security bugs and protect the rest of the operating system from being compromised.