All about Microsoft's Edge Browser: Extensions, high performance asm.js, and no more ActiveX
And no chance of open source any time soon. — Microsoft has spent the past few days talking about the new browser formerly known as Project Spartan: what it will do, what it won't do, and what it won't do yet but will do soon.
Context & Ripple Effects
Edge's public identity has been assembling all year: January brought both the new EdgeHTML rendering engine built from scratch for Spartan and confirmation that the browser would get extensions, followed by an April hands-on noting extensions weren't available yet. This piece fills in the platform details around that skeleton — how extensions will work, why asm.js matters for performance, and what dies with ActiveX.
The stakes are distribution: Microsoft had already committed to shipping Edge on every Windows 10 device by end of April, which makes each capability decision here a default-setting decision for the entire Windows install base rather than an opt-in feature.
First-order effects
- Extension developers now have a supported path into Microsoft's browser, but under whatever API model Edge ships with rather than the free-for-all ActiveX model IE offered.
- Enterprise sites and internal tools still leaning on ActiveX controls face a forced migration when Windows 10 lands with Edge as the default, alongside the earlier loss of Silverlight.
Second-order effects
- Plugin-dependent vendors lose their last major IE-compatible host as Microsoft strips out ActiveX and confirms no Silverlight support — the same pressure that pushed Flash-era content toward HTML5 alternatives.
- Chrome and Firefox face a re-armed competitor on their home turf: if Microsoft's own benchmarks hold up, extension parity removes the main practical reason power users stayed away.
Third-order effects
- If Edge ships without ActiveX or open source and still meets competitors' performance marks, the industry's direction is a small set of engines converging on web standards and sandboxed APIs — with legacy plugin ecosystems like Silverlight's left to fade rather than be ported forward.
The trend: Browsers are shedding proprietary plugin architectures like ActiveX and Silverlight in favor of standardized, sandboxed extension and scripting models — and Microsoft's Windows 10 default is forcing the transition faster than market choice would.