In the latest Microsoft rumors, the Redmond, Wash.-based tech giant is said to be working on a new web browser that goes by the name "Spartan."

Sources with knowledge of the situation say Spartan will not be connected to Internet Explorer, and will instead be a new, light-weight browser, according to ZDNet Mary Jo Foley. Microsoft's Chakra JavaScript engine, as well as its Trident rendering engine, were also said to be included.

Reports about Spartan date back months, with Neowin's Brad Sams saying in September that the browser will look and feel more like Chrome and Firefox and will support extensions. Microsoft Student partner lead Thomas Nigro said on Twitter earlier this month that he heard about the browser being developed while listening to an episode of the LiveTile podcast.

The latest rumor comes at a time when Internet Explorer doesn't hold the position in the desktop or mobile market it used to have, Wired reported. The desktop market is currently dominated by Mozilla Firefox and Google Chrome, while the top spot in the mobile market is currently being fought over between Apple Safari, Google Chrome and Google's Android browser.

As of now, Spartan serves as a codename, Foley said, and the name the browser will have in its debut has yet to be revealed.

The new browser is expected to make its debut on Jan. 21, the same day Microsoft is expected to debut its Windows 10 operating system. Sources say Spartan will be available on desktops, phones and tablets, but it is not yet known if it will be available on Android, iOS or other competing operating systems.