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.

Read next: Our review of Windows 10.

Cortana is coming to your browser

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.

Spartan will be a Windows Store app for regular updates

Spartan is designed to be a single browser across PCs, tablets, and phones. We’re told that Microsoft will make Spartan a Windows Store app, enabling the company to quickly and easily update the browser in future. ZDNet previously reported that Microsoft will continue to include Internet Explorer in Windows 10, and we understand this will be primarily for legacy compatibility reasons. Spartan is the main browser in Windows 10, and most users will be accessing the web using it. While Spartan will be a Windows Store app, we understand Microsoft isn’t planning to make it a universal app initially. One version of Spartan will be available in the Store as a desktop app, and another as a modern app for tablets and phones. Both will be updated regularly with identical features.

Microsoft is planning to keep the look and feel of Spartan very similar across phones, tablets, and PCs. The desktop version looks like a simplified version of Chrome, with a tabbed interface above the address bar, alongside options to go back, forward, and refresh a page. It’s all designed to look lightweight, without the bloat typically associated with older versions of Internet Explorer. While the Spartan name is a codename, it’s not clear if Microsoft plans to continue the Internet Explorer branding with its new browser. That naming and other features of Spartan could play a part in Microsoft’s Windows 10 event on January 21st. Microsoft is planning to detail the consumer features of Windows 10 at its press event later this month, including its phone and tablet features.

We reached out to Microsoft for comment on its Windows 10 browser plans, but a spokesperson says the company has "nothing to share."