As the July 29 scheduled release date for Windows 10 draws closer, Microsoft-watchers are spotting signs of close-to-final builds of the new operating system. At least one candidate for the RTM (release-to-manufacturing) version of Windows 10 -- Build 10176 -- was posted Sunday on building tracking site BuildFeed.

Windows 10 will be the "last" version of Windows, as the software from now on will be upgraded and updated on an ongoing basis rather than in discrete generations, according to Microsoft. The change reflects Microsoft's new as-a-service model for Windows.

Microsoft released three new builds of Windows 10 to its Insider testers last week. Build 10158 was announced on June 29, Build 10159 came out Tuesday and Build 10162 was released on Thursday.

'Listening to 5 Million Insiders'

Quoting "sources familiar with Microsoft's plans," The Verge on Monday reported that a market-ready build of Windows 10 is likely to be completed later this week. However, Microsoft will continue working to fix bugs in the new software until the final release date on July 29.

Windows 10 will be rolled out in phases, according to Terry Myerson, executive vice president of Microsoft's Operating Systems Group. The new operating system will go out to Windows Insiders first, and will then be released in waves to users who have made reservations for the update online. Enterprise users will begin seeing Windows 10 on August 1, he added.

"In our testing of millions of systems, we're seeing full compatibility today with the vast majority of Windows 8x and Windows 7x systems," Myerson said in a blog post. "We are also rigorously testing and listening to every signal from our 5 million Windows Insiders on the quality and readiness of Windows 10."

Smarter Cortana, Biometric Security and More

Microsoft has said Windows 10 will be groundbreaking for several reasons. One major feature will be its status as a universal OS that will use the same code and deliver the same look and feel across all types of devices. The new operating system will also support a range of new features and functions, including Edge, the successor to Microsoft's Internet Explorer Web browser.

Other new features arriving with Windows 10 include an improved and smarter Cortana personal digital assistant, the Windows Hello biometric security Relevant Products/Services app, a Windows 10 beta version of the game Minecraft and improved networking APIs.

Windows 10 will also bring back a number of features that users have missed since the release of Windows 8 and 8.1, including the Start menu. It will also support Windows Continuum, which will let users easily and seamlessly transition their computing from PCs to tablets to phones, and HoloLens, a wearable device for holographic computing that has not yet been scheduled for release.