content: Internet Explorer was slaughtered by the rise of open source browsers. The most obvious cause is the lack of extensions(if it supported NoScript, AdBlock, etc, it might've had a chance), but it also sucks on JavaScript performance(I switched my browser at work from IE to Palemoon and noticed our ticketing system sped up a good deal). Edge is already designed for easier porting of extensions from Firefox and Chrome, so by open sourcing this and encouraging others to use it in their projects, they get to benefit from their working to optimize it and avoid falling behind again. Those clever bastards are turning the community into Edge's sword and shield.