Here are some interesting info about Spartan from today’s Internet Explorer Dev Chat Q&A Session by Microsoft News Windows 10
Spartan may have its address bar at the bottom after all and other UI changes by Michael Allison News, Slider, Windows Phone
Microsoft, Windows 10 Windows 10 Build 9926: The New Rendering Engine In Spartan Browser Shows Massive Performance Improvements
Microsoft, Slider, Windows 10 One More Report Reveals New Features Coming In ‘Spartan’ Web Browser In Windows 10