Why What You're Reading About Blink Is Probably Wrong
By now you've seen the news about Blink on HN or Techmeme or wherever. At this moment, every pundit and sage is attempting to write their angle into the annoucement and tell you "what it means". The worst of these will try to link-bait some "hot" business or tech phrase into the title. True hacks will weave a Google X and Glass reference into it, or pawn off some "GOOGLE WEB OF DART AND NACL AND EVIL" paranoia as prescience (sans evidence, of course). The more clueful of the ink-stained clan will constrain themselves to objective reality and instead pen screeds for/against diversity despite it being a well-studied topic to which they're not adding much.
May the deities we've invented forgive us for the tripe we're about to sell each other as "news".
What's bound to be missing in most of this coverage is what's plainly said, if not in so many words, in the official blog post: going faster matters.
Not (just) code execution, but cycle times: how long does it take you to build a thing you can try out, poke at, improve, or demolish? We mere humans do better when we have directness of action. This is what Bret Victor points us towards -- the inevitable constraints of our ape-derived brains. Directness of action matters, and when you're swimming through build files for dozens of platforms you don't work on, that's a step away from directness. When you're working to fix or prevent regressions you can't test against, that's a step away. When compiles and checkouts take too long, that's a step away. When landing a patch in both WebKit and Chromium stretches into a multi-day dance of flags, stub implementations, and dep-rolls, that's many steps away. And each step hurts by a more-than-constant factor.
This hit home for me when I got my first workstation refresh. I'd been working on Chrome on Windows for nearly a year in preparation for the Chrome Frame release, and all the while I'd been hesitant to ask for one of the shiny new boxes that the systems people were peddling like good-for-you-crack -- who the hell was I to ask for new hardware? They just gave me this shiny many-core thing a year ago, after all. And I had a linux box besides. And a 30" monitor. What sort of unthankful bastard asks for more? Besides, as the junior member of the team, surely somebody else should get the allocation first.
Months later they gave me one anyway. Not ungrateful, I viewed the new system with trepidation: it'd take a while to set up and I was in the middle of a marathon weekend debugging session over a crazy-tastic re-entracy bug in a GCF interaction with
urlmon.dll that was blocking the GCF launch. If there was a wrong time to change horses, surely this was it. At some point it dawned that 5-10 minute link times provided enough time to start staging/configuring at the shiny i7 box.
A couple of hours later the old box was still force-heating the eerily dark, silent, 80-degree floor of the SF office -- it wasn't until a couple of weeks later that I mastered the after-hours A/C -- when my new, even hotter workstation had an OS, a checkout, compiler, and WinDBG + cargo-culted symserver config. One build on the new box and I was hooked.
5-10 minute links went to 1-2...and less in many cases because I could now enable incremental linking! And HT really worked on the i7's, cutting build times further. Hot damn! In what felt like no-time at all, my drudgery turned to sleuthing/debugging bliss (if there is such a thing). I could make code changes, compile them, and be working with the results in less time than it took to make coffee. Being able to make changes and then feel them near-instantly turned the tide, keeping me in the loop longer, letting me explore faster, and making me less afraid to change things for fear of the time it would take to roll back to a previous state. It wasn't the webdev nirvana of ctrl-r, but it was so liberating that it nearly felt that way. What had been a week-long investigation was wrapped up in a day. The launch was un-blocked (at least by that bug) and the world seemed new.
The difference was directness.
The same story repeats itself over and over again throughout the history of Chrome: shared-library builds, ever-faster workstations, trybots and then faster trybots, gyp (instead of Scons), many different forms of distributed builds, make builds for gyp (courtesy of Evan Martin), clang, and of course ninja (also Evan...dude's a frickin hero). Did I mention faster workstations? They've made all the same sort of liberating difference. Truly and honestly, in ways I cannot describe to someone who has not felt the difference between ctrl-r development and the traditional Visual Studio build of a massive project, these are the things that change your life for the better when you're lashed to the mast of a massive C++ behemoth.
If there is wisdom in the Chrome team, it is that these projects are not only recognized as important, but the very best engineers volunteer to take them on. They seem thankless, but Chrome is an environment that rewards this sort of group-adaptive behavior: the highest good you can do as an engineer is to make your fellow engineers more productive.
And that's what you're missing from everything else you're reading about this announcement today. To make a better platform faster, you must be able to iterate faster. Steps away from that are steps away from a better platform. Today's WebKit defeats that imperative in ways large and small. It's not anybody's fault, but it does need to change. And changing it will allow us to iterate faster, working through the annealing process that takes a good idea from drawing board to API to refined feature. We've always enjoyed this freedom in the Chromey bits of Chrome, and unleashing Chrome's Web Platform team will deliver the same sorts of benefits to the web platform that faster iteration and cycle times have enabled at the application level in Chrome.
Why couldn't those cycle-time-improving changes happen inside WebKit? After all, much work has happened in the past 4 years (often by Googlers) to improve the directness of WebKit work: EWS bots, better code review flow, improved scripts and tools for managing checkins, the commit queue itself. The results have been impressive and have enabled huge growth and adoption by porters. WebKit now supports multiple multi-process architecture designs, something like a half-dozen network stack plug-ins, and similar diversity at every point where the engine calls back to outside systems for low-level implementation (GPU, network, storage, databases, fonts...you name it). The community is now committed to enabling porters, and due to WebKit's low-ish level of abstraction each new port raises the tax paid by every other port. As James Robinson has observed, this diversity creates an ongoing drag when the dependencies are intertwined with core APIs in such a way that they can bite you every time you go to make a change. The Content API boundary is Blink's higher-level "embedding" layer and encapsulates all of those concerns, enabling much cleaner lines of sight through the codebase and the removal of abstractions that seek only to triangulate between opaque constraints of other ports. Blink gives developers much more assurance that when they change something, it's only affecting the things they think it's affecting. Moving without fear is the secret of all good programming. Putting your team in a position to move with more surety and less fear is hugely enabling.
Yes, there are losses. Separating ourselves from a community of hugely talented people who have worked with us for years to build a web engine is not easy. The decision was wrenching. We'll miss their insight, intelligence, and experience. In all honesty, we may have paid too high a price for too long because of this desire to stay close to WebKit. But whatever the "right" timing may have been, the good that will come from this outweighs the ill in my mind.
Others will cover better than I can how this won't affect your day-to-day experience of WebKit-derived browser testing, or how it won't change the feature-set of Chrome over-night, or how the new feature governance process is more open and transparent. But the most important thing is that we'll all be going faster, either directly via Blink-embedding browsers or via benchmarks and standards conformance shaming. You won't feel it overnight, but it's the sort of change in model that enables concrete changes in architecture and performance and that is something to cheer about -- change is the predicate for positive change, after all.