SFHTML5 Meetup - Engineering Microsoft Edge for the web of today and tomorrow

Editor's Notes

• #7: Why do we want the web to win in this fight?
• #14: TODO: add more splitting and animate between them
• #24: Anyone remember Mozilla 5.0? It’s actually Netscape Navigator 6, from the year 2000
• #26: Actual UA sniffing example
• #31: We receive an amazing amount of data on site compatibility and I’ll talk more about that in a moment. To make sense of it all, we use a classification system to prioritize what we invest in to maximize its impact. At the top of this priority list is what we call “Interop 0”, these are sites that worked in IE11 but no longer work in Project Spartan. Sometimes this is because we goofed, but most often it’s because we’re now getting interoperable content and need to make a change to behave like other browsers. So beyond just ensuring a site continues to work, we’re also reducing the delta in behavior of our engine when compared with other engines. Next there is Interop 1 issues, these are ones that affect Project Spartan but also were broken in IE11. Often these are new standards that are being adopted by the web. So we implement them. Next we have Interop 2, these are things that are typically emerging in standards. They may or may not be supported by any browser at the moment. Generally, sites aren’t yet adopting these features quite yet but we anticipate they will in the near future. Finally there’s the Interop 3 bucket, these are things that are still in the idea or iteration stage or are supported but deprecated in other browsers with very low or 0 usage on the web. Some features in this bucket will eventually make it to Interop 2 once standards solidify and developer interest increases. Others are on their way out and may never get implemented in our engine.
• #32: Feature 602898 http://www.w3.org/TR/css3-fonts/ CSS Fonts Module Level 3 W3C Candidate Recommendation 3 October 2013 4.9 Font fetching requirements For font loads, user agents must use the potentially CORS-enabled fetch method defined by the [HTML5] specification for URL's defined within @font-face rules. When fetching, user agents must use "Anonymous" mode, set the referrer source to the stylesheet's URL and set the origin to the URL of the containing document. The implications of this for authors are that fonts will typically not be loaded cross-origin unless authors specifically takes steps to permit cross-origin loads. Sites can explicitly allow cross-site loading of font data using the Access-Control-Allow-Origin HTTP header. For other schemes, no explicit mechanism to allow cross-origin loading, beyond what is permitted by the potentially CORS-enabled fetch method, is defined or required.
• #39: It makes developers really happy to remove code. Like really happy. I tried to enumerate all the IEisms we’ve removed, but I just couldn’t.
• #40: So I made a diff. Let’s take a second to review the non-interoperable IE’isms we’ve removed thus far.
• #42: “So we’re done once each one of them browses 11 million pages”
• #43: [Diagram for crawler + instrumentation] [Perhaps animate fade/in out series of stats] [Live demo Finder – “someone give me a popular DOM API”]
• #51: Status tracks 193 standards or proposals – this doesn’t include the baseline stuff supported IE8+ The HTML5 spec alone is 693 pages when printed. Microsoft has 90 members in 58 different Working Groups (avg amongst top 5 browser makers is ~80) So you can imagine how easy it is for browsers to behave differently or for specs to have mistakes.