Microsoft's much-rumored Spartan browser is now finally official, as the company offered more details on the project at its Windows 10 event on Jan. 21.

For years, Internet Explorer has been losing market share despite Microsoft's efforts to modernize the browser and match the capabilities of Google's Chrome and Mozilla's Firefox. Microsoft is not giving up on Internet Explorer, but the latest Windows 10 will also bring another browser to the table. In other words, Internet Explorer now has a new rival, and it comes from its own back yard.

Microsoft's new browser is codenamed Project Spartan and is designed to be faster, handle modern Web-programming standards with ease, and put content front and center. Moreover, Project Spartan also includes Cortana, marking the first time such a digital assistant escapes the mobile realm and reaches the desktop. Additionally, Spartan will allow users to annotate Web pages with a stylus or mouse, share things through email and social media, or save content to the cloud.

"A new web experience for Windows 10 - Code-named 'Project Spartan,' the next generation browser was built with greater interoperability, reliability and discoverability, with a new look and feel built just for Windows 10," Microsoft touts in a new post on the Windows blog. "Advanced features include the ability to annotate by keyboard or pen directly on the webpage and easily share with friends, a reading view that is distraction free, displaying the article in a simplified layout for a great reading experience for Web articles online and offline, and the integration of Cortana for finding and doing things online faster."

The new Windows 10 will still include Internet Explorer, but Spartan will be the main focus in the new OS. The company did not explain the relationship between Spartan and Internet Explorer, but it seems that the two browser experiences will coexist, allowing consumers to choose which one they prefer to use. It remains to be seen just how this dual-browser approach will work for Microsoft, but Spartan is expected to be more popular than Internet Explorer.

The new Project Spartan browser will also work on mobile devices, which should further boost its appeal over Internet Explorer as increasingly more consumers now rely on smartphones and tablets for browsing. For more information about Windows 10, meanwhile, check out the video below.