What remained was a clean slate. A modern web platform built with interoperability and standards at its core. From there, we began a major investment in interoperability with other modern browsers to ensure that developers don’t have to deal with cross-browser inconsistencies. To date, we’ve fixed over 3000 interoperability issues (some dating back to code written in the 90’s) on top of the over 40 new web standards we’re working on. For example, longstanding innerHTML issues are now fixed. Even recent standards, like Flexbox, are getting renewed love so that the new engine matches the latest spec (this will show up in a future Windows 10 preview build). Project Spartan will also have an updated version of the F12 developer tools. A few of my personal favorites that are in the preview builds or on their way: