Even though screen shots and videos of the next version of Windows, codenamed 'Threshold,' have leaked , relatively little information about the next version of Internet Explorer (IE) has gone public so far.

Neowin.net's Brad Sams noted that the next IE release — which may be known as IE 12 if Microsoft continues to follow its current naming conventions — is expected to look more like a cross between Chrome and Firefox, with an alleged new tab layout and support for browser extensions.

My sources say that the codename for this next IE release is "Spartan." One of my contacts caught a glimpse of a "zSpartan" app that can be seen in one of the leaked Threshold screen shots from ComputerBase and WinFuture. I've embedded that screen shot in this post. zSpartan is visible in the list of programs on the Start Menu, just below the word "Video." (Before Microsoft went public about its Cortana personal digital assistant for Windows Phone, there also were similar sightings of a "zCortana" app. )

There's also a mention of "Spartan" in a recent Microsoft job post for a software development engineer for a new Bing app linking and task completion team that adds a bit more detail.

The Bing app linking and task completion team is focused on "discovering and indexing services on the web and within native apps," as well as "understanding the intents of services as actions" using machine learning and big-data analysis techniques. The team will be charged with "shipping task completion features via web/app services on bing.com, Cortana, Bing search apps, Spartan/Office/Skype/etc. (emphasis mine) and external search API," the job post states.

The job post puts the new app-completion team's role in context:

"The emergence of online services has extended web as an information repository to where users can take actions and complete tasks end to end, such as buying movie tickets, reserving a restaurant table, borrowing books, and getting a taxi. This trend is accelerated by the mobile devices, equipped with the mobile web to keep user always online, multiple sensors to extend user inputs from texts to speech, images, location and connect online to offline, cloud computation to enable intelligent inferences and large scale data mining, and native apps to deliver compelling user experiences. With this, search engine's role is to connect people with services, turn intentions into actions lightning fast, and eventually make your mobile devices as your personal task assistant."

There are other mentions of Spartan in Microsoft's job posts which may or may not be related to IE Spartan. There are a couple of openings on an Information Platform Group (IPG) known as SPARTANs, or Special Projects and Resources Team (SPARTAN). While the SPARTANs seem to be a part of Microsoft's Advertising group, they also seem to have some goals that could dovetail with those working on IE Spartan.

Here's an excerpt from one of the IPG SPARTANs job posts:

"With a set of rich information understanding services Cortana (conversation/user intent), Bing Index (web/user intent), Satori (entity), Ads (advertiser intent) and a high velocity experimentation framework, IPG is the cornerstone for providing rich information based services and solution for the future of Microsoft. As the team focuses on Digital Work/Digital Life scenarios, there will be many strategic projects that will emerge."

Back to IE Spartan.

It's going to be interesting to see how Microsoft decides to implement an extensions model in the next IE release, given its patchy support for plug-ins.

I don't see anything on Microsoft's own list of IE features coming in future releases that looks like it could be extension-related. (If any of you readers see anything, let me know.) This list is detailed, yet incomplete , Microsoft officials themselves have acknowledged, and isn't limited to what's in IE 12 or whatever the next release of IE is called.

I will throw out a bit of pure speculation on my part. The rest of this post is just me attempting to connect dots, which may or may not be connectable.

What if Microsoft has found a way to use some of the browser-related work that Microsoft Research has done around a project known as XAX to further the browser plug-in/extension model?

Here's an excerpt from a Microsoft Research paper about the team's work XAX:

"Xax is a browser plugin model that enables developers to leverage existing tools, libraries, and entire programs to deliver feature-rich applications on the web. Xax employs a novel combination of mechanisms that collectively provide security, OS-independence, performance, and support for legacy code. These mechanisms include memory-isolated native code execution behind a narrow syscall interface, an abstraction layer that provides a consistent binary interface across operating systems, system services via hooks to existing browser mechanisms, and lightweight modifications to existing tool chains and code bases."

In short, XAX allows users to run x86 native code as a browser extension using "picoprocesses," which are a micro-virtualization framework.

Where else in Microsoft-land has the notion of picoprocesses shown up? Drawbridge — another Microsoft Research project, and possible successor to XAX. Drawbridge provides a new form of virtualization for application sandboxing , combining a picoprocess and a library OS.

There already are picoprocess trails in Windows 8.1, by the way... just to fuel speculation further.