Microsoft is coming up with a new web browser for its soon-to-be released Windows 10, and it will not be called Internet Explorer 12. 

ZDNet's Mary Jo Foley revealed the information about the new web browser. Based on her sources, the "new, light-weight browser" is called Spartan, which at present is just a codename. The browser might be featured during the Microsoft event on Jan. 21, where new information about Windows 10 will be unveiled as well. Her sources are not sure, however, if the Spartan will be functional enough to be included in the upcoming Windows 10 Technical Preview, which will be available for beta testers early this year.  It's likely that the test build will make an appearance much later. 

The alleged new browser will come with an extension support, a version that is compatible with mobile devices, as well as a separate desktop. The browser will also use the Chakra Javascript engine from Microsoft, as well as a page rendering engine from Trident. 

Some of the earlier reports mentioned that the new browser will have the same look and feel as Firefox and Chrome, and it will also enable the use of extensions. Yet the alleged Spartan browser will have to compete against these two leading web browsers along with Safari from Apple. 

But even if the Spartan will be featured during the event, the browser will roll out at a much later date since Windows 10 is not expected to come out until fall. 

In August 2015, Microsoft's Internet Explorer will be celebrating its 20th anniversary. It is not certain, however, if the alleged Spartan will take over Internet Explorer completely, or if it will just be an alternative to IE. Fowley's sources say that Spartan will be available for Windows 10-based devices but IE 11 might still be present for backward-compatibility.