Microsoft's 'Spartan' browser is shaping up, leaks show

More rumored details are leaking about Microsoft's new browser, codenamed Spartan, that will be a key piece of its Windows 10 platform.

Spartan, which will use the Trident rendering engine and the Chakra JavaScript engine that are part of Internet Explorer, is not just another new IE release, sources told me last week. It is expected to look and work more like lightweight browsers such as Google's Chrome and Mozilla's Firefox, sources have said. It allegedly will support extensions, unlike IE.

This week, a BGR report claimed Spartan will be integrated with Microsoft's Cortana personal digital assistant technology. One of my sources says this is accurate information, and the Verge is hearing the same.

Given that Microsoft is building Cortana support into Windows 10 (both desktop and the coming mobile release for smaller tablets and Windows Phones), Cortana integration makes a lot of sense. On phones, especially, the ability to tell a browser to "go to Facebook" or "check the status of British Air Flight 103" would be handy.

Spartan will include digital inking support "that allows Windows 10 users to annotate a web page with a stylus and send the notes and annotations to a friend or colleague," according to the Verge. Annotated web pages will be able to be stored in OneDrive "that can be accessed by any browser across multiple platforms," the Verge reported.

The Verge also reported that Spartan will allow users to group tabs however they want, splitting work and personal tabs if they so desire. One of my contacts confirmed there will likely be a "grouped tabs" feature in Spartan to help users better maintain the context of where links came from. Spartan may allow users to open multiple sites in grouped tabs together, so they can do things like compare prices of a new phone without having to switch between tabs, my source said.

Tech news site Neowin posted earlier this week a mockup based on what were said to be actual screenshots of an early version of Spartan. One of my sources said that this screen shot and mockup accurately reflect how Spartan is evolving from a user interface standpoint. However, because Spartan was designed using many of the new UI design elements for Windows 10 that haven't yet been released publicly, it's hard to get an accurate picture right now of what Spartan ultimately may look like, one of my contacts said.

Neowin also noted that Spartan would replace "Modern" IE, aka the Windows Store/Metro Style IE variant that was part of Windows 8. The Verge, meanwhile, reported that sources say Spartan will be a Windows Store app -- and one that will actually be downloadable from the store.

Right now, IE isn't an app that Windows 8 or Windows Phone users get via the Windows Store or Windows Phone Store; it's part of the OS platform. By making Spartan an app, Microsoft should be able to update it more quickly.

As I noted last week -- but which a number of bloggers and reporters who covered my post misreported -- Microsoft is not killing IE and replacing it with Spartan. IE will remain an option available for Windows 10 PCs and desktops for users who want and need it. But Spartan will be installable and work on Windows 10 PCs, desktops, tablets and phones.

An interesting aside: one of the reasons Spartan is still using Trident (and not an alternative like Webkit) is to help with site compatibility. If Spartan detects a site was written for an old version of IE, it can use Trident to render it like IE would, one of my contacts said.

Microsoft is expected to show off and discuss Spartan at least to some extent during the January 21 Windows 10 preview event it is hosting in its home city of Redmond, Wash.

This story originally posted as "Microsoft's 'Spartan' browser: More details leak" on ZDNet.