When Microsoft first announced Windows 10, the tech world was abuzz with speculation about what changes the new operating system would bring. One of the biggest questions on everyone's mind was what would happen to Internet Explorer, Microsoft's long-standing web browser that had been a staple of the Windows ecosystem for decades. As it turned out, Microsoft had been secretly working on a new browser project codenamed "Spartan," which would eventually go on to become Microsoft Edge.

Project Spartan was first announced in January 2015, when Microsoft's Joe Belfiore took the stage at a Windows 10 event to unveil the company's latest plans for web browsing. According to Belfiore, Project Spartan was designed from the ground up to provide a faster, more streamlined browsing experience that would make it easier for users to access the web.

At the time, many speculated that Project Spartan would simply be a rebranded version of Internet Explorer, with a few minor tweaks under the hood. But as it turned out, Microsoft had much bigger plans for the new browser. Project Spartan was a clean break from Internet Explorer, with a new rendering engine, a new JavaScript engine, and even a new user interface.

One of the biggest changes in Project Spartan was the use of the EdgeHTML rendering engine, which was designed to provide faster and more efficient webpage rendering. The new engine was also more secure, with a sandboxed architecture that made it harder for malware to infect the browser.

Another key feature of Project Spartan was its focus on web standards. Unlike Internet Explorer, which had long been criticized for its lack of support for web standards, Project Spartan was designed to be fully compliant with modern web technologies like HTML5 and CSS3. This made it easier for developers to build web pages that would work correctly in the browser, without having to resort to hacks and workarounds.

When Project Spartan was finally released as part of Windows 10 in July 2015, it was clear that Microsoft had a game-changer on its hands. The new browser was fast, secure, and fully featured, with support for everything from extensions to built-in PDF viewing. But despite the many improvements, Project Spartan was not without its challenges. One of the biggest criticisms of the browser was its lack of support for legacy Internet Explorer features, which made it difficult for some enterprise customers to migrate.

Despite these challenges, Project Spartan - now rebranded as Microsoft Edge - has gone on to become one of the most popular browsers in the world. With its fast performance, secure architecture, and focus on web standards, it's clear that Microsoft has finally gotten the browser right. And as the company continues to evolve and improve Edge, it's clear that the best is yet to come.