Microsoft is planning to radically overhaul its web browser in Windows 10. Sources familiar with the company's Windows plans tell The Verge that the new browser, codenamed Spartan, will include a host of new features not found in rival browsers. Chief among the plans for Spartan is new 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. The web note service will be powered by Microsoft's OneDrive cloud storage, meaning notes will be stored on a copy of a web page that can be accessed by any browser across multiple platforms. As annotations are shared, multiple users can doodle on a web page and share edits and annotations between groups.

A second major feature for Spartan will be the integration of Microsoft's Cortana digital assistant. Microsoft is planning to use Cortana to surface information on flights, hotel bookings, package tracking, and other data within the traditional address bar. If you use Cortana to track a particular flight and start to search for "American Airlines" in the browser address bar, it will automatically display tracked flights and allow Spartan users to view the status of the flight directly. It's a subtle addition, but you'll also be able to access Cortana search directly from the new tab interface in Spartan. Cortana integration in the Spartan browser is planned to replace every instance of the existing Bing methods in Internet Explorer.

Other features include a new way to group tabs together to declutter the occasionally messy interface of multiple browser tabs. Spartan will allow users to group tabs however they want, making it easier, for example, to split up personal tabs from work ones. Microsoft also originally planned to allow Spartan to support custom themes, but we understand the company has dropped this for the final new browser in Windows 10. Such support may arrive in future updates.