Microsoft Edge's JavaScript engine to go open-source

https://blogs.windows.com/msedgedev/2015/12/05/open-source-chakra-core/

by clarle • 11 years ago

852 256 11 years ago

blogs.windows.com

sdegutis• 11 years ago

Wow. They're really serious about changing their philosophy aren't they. Using Github for their stuff, making and open sourcing Visual Studio Code, other stuff I can't remember, and now this.

Inthenameofmine• 11 years ago

If they go full SaaS I would not be surprized if they go Open Source on Windows itself, seriously. I think for that to happen Nadella needs one big win/turnaround and the shareholders might be on board.

oblio7• 11 years ago

Well, it seems feasible if they take out enterprisey features. For example Windows without AD support could be an option. Or without remote desktop support.

The hobbyists would use it as is but no company would touch it without support anyway.

krylon2• 11 years ago

Unless my memory is playing tricks on me, a couple of months back, Mark Russinovich (of SysInternals fame) gave a talk somewhere and mentioned that they were looking into that.

Sounds kind of strange to say it out loud, though. ;-)

outside1234• 11 years ago

I was literally blown away by Visual Studio Code. It is an amazing editor. I haven't opened sublime since.

eecks• 11 years ago

I prefer Atom

ameen3• 11 years ago

I'm still pretty much on Atom, but yes VSC wasn't expected. I would migrate if most of my plugins were available on there.

corford• 11 years ago

I really wanted to like VSCode but couldn't get over the "working files" paradigm and consequent lack of tabs :(

Have gone back to Sublime 3 for now but if the VSCode devs ever decided to support tabs I'd switch.

ckluis• 11 years ago

I wish it could keep all the file info between quiting/opening and auto-saving similar to the way that sublime does.

ameen3• 11 years ago

They're aware of the permeance of open-source in current tech scene and want to be a part of it than fight it. Not many startups (except for DreamSpark, BizSpark, and Seattle/Redmond based ones) build on MS stack nowadays. MS audits are dreaded (thanks to Oracle for showing the way) and a diversion for a growing startup. It's better to steer clear of MS & other proprietary tech whilst building a startup.

They're embracing startups since they need them and are changing their business models to cater better to smaller startups than the behemoth enterprises with Office 365, Azure, etc.

gtirloni• 11 years ago

Edge is certainly much faster than Chrome/Firefox for JS processing that I wish I could use it on Linux. Looks like that might be happening. Really great news.

I didn't know Node.js could use anything but v8. This is also very nice.

ameen3• 11 years ago

I think theoretically Node.js could work without V8, and guess some of MS's work for IoT was indeed that (swapping V8 for Chakra).

frik4• 11 years ago

There used to be an Mozilla spidermonley based node.js too, though it isn't maintained atm.

https://news.ycombinator.com/item?id=2469786

https://github.com/zpao/spidernode

Klathmon5• 11 years ago

I'm not sure where the hangup is, but I've found that Edge is fast as hell for initial page startup, but lags behind quite a lot when under heavy load.

I've seen the benchmarks but in my experience it just... lags...

For example, on the kangax ES6 compatibility table [1]. On chrome clicking a column takes less than a second, on Edge (i'm on an up-to-date Windows 10 machine, no preview stuff) it loads faster than in chrome, but takes 3+ seconds to switch between columns.

Even some of the stuff i've written acts similarly, and i can't figure out why.

[1]https://kangax.github.io/compat-table/es6/

white-flame• 11 years ago

I know between Chrome and Firefox for a particular project of mine (which is a bit old now), Firefox ran raw JS faster, but Chrome could update its DOM faster. FF would spend much more time when many updates needed to happen in a large column of divs (10k+). Raw JS speed isn't everything.

nojvek3• 11 years ago

Chrome's Dom and painting engine is faster than Edge. That being said Edge just came out recently and is still bogged down by some of IE 11 stuff like the trident layout engine. I'm sure they are really invested to make it faster.

Think about it, Microsoft really wants bing to succeed, for it to happen, Edge has to succeed so I'm sure they are putting their best minds behind it. Its a matter of time.

Sir_Cmpwn2• 11 years ago

Wow, I'll admit that I haven't been looking at Edge simply because of the IE stigma, but this blog post impressed me. 90% ES6 support? More so than Babel? Awesome. And it's getting open sourced! I hope to see it ported to the Unixes. Perhaps Servo+Chakra could be a thing?

nly2• 11 years ago

Servo is a rendering engine written in Rust, why would it choose Chakra, which is written in C++, over WebKit, which is written in C++?

adrianlmm4• 11 years ago

Servo is use in production by any browser? or any Project like Chakra? or is just an experiment till now?

Sir_Cmpwn2• 11 years ago

Servo currently uses SpiderMonkey as its JavaScript engine (SpiderMonkey is the Firefox JS engine). Sure, a JavaScript engine written at Rust would be useful at some point, but right now that's not on their roadmap.

Manishearth7• 11 years ago

You're comparing apples and oranges here.

Rendering engines (all in C++ except Servo):

- Servo

- Blink (Chrome/Opera)

- Trident/Spartan (IE/Edge)

- Webkit (Safari)

JS engines:

- Spidermonkey (used by Servo and Firefox)

- Chakra (used by Trident/Edge)

- V8 (used by Blink, also by Node)

Servo already uses a JS engine in C++ because a Rust JS engine is a huge undertaking in itself (see [1])

It does make sense to try out Chakra or V8 for Servo. It's probably a lot of work, though. And there may not be a net gain out of that (We have access to in-house spidermonkey know-how, none of that for the others).

[1] https://news.ycombinator.com/item?id=10682274

whatever_dude4• 11 years ago

Initially I thought Edge would just be IE with (yet another) skin, but I have to say, it's absurdly fast and lightweight. It's still not my main browser as I'm now too deeply entrenched in Chrome for development, but it makes me really happy to know they're actually pushing the web ahead.

benaadams• 11 years ago

Give the JavaScript Browser a go; is Edge render + Chakra, but has a faster starup - Also OSS by MS O_o https://www.microsoft.com/en-gb/store/apps/javascript-browse...

PeCaN2• 11 years ago

I find its UI quite annoying and its tab management really poor, but technologically it's really solid. I've noticed it seems to handle HTML5 video more smoothly than Firefox (I rarely use Chrome so I can't really comment on it).

Manishearth7• 11 years ago

Perhaps Servo+Chakra could be a thing?

Sounds like a lot of work (not to say it's not possible or interesting). Our bindings code[1] is pretty complicated already. It depends highly on how Chakra deals with things internally -- if it's similar to SpiderMonkey; I'd be interested in having a look. Might become a fun project :)

Without a reference open source DOM implementation (which we have for SM -- Firefox's DOM), we'd also need good docs for the Chakra API. No idea if that exists.

[1] https://github.com/servo/servo/tree/master/components/script...

hiteshk_msft3• 11 years ago

Engineer on Chakra here- are these the docs you're looking for? https://msdn.microsoft.com/en-us/library/dn249552(v=vs.94).a...

miralabs• 11 years ago

I wonder if in the future node will enable swappable js engine edit: ok just found this https://news.ycombinator.com/item?id=9534138

Klathmon5• 11 years ago

I've hoped for this since it's inception.

It gives the benefits of having multiple competing implementations but unlike the browser platform we (the developers) get to choose which one we use.

ndesaulniers3• 11 years ago

Native addons and even Node core are too tightly coupled with v8. NAN will need an overhaul.

adrianlmm4• 11 years ago

I'd like to see Node.js using Chkara by default, V8 developers have showed that they don't care much about Node.js, they are more interested in Chrome, and MS have showed more interest in Node.js than Google and I'm sure it will be better for all, fingers crossed.

frik4• 11 years ago

I don't. A lot of code out in the wild already relies on v8, and won't work with Chkara. Node 5 is up-to-date with v8. Though, I would like to see Mozilla devsvwpuld revives the unofficial spidermonkey Node.js support (https://news.ycombinator.com/item?id=2469786 , https://github.com/zpao/spidernode ).

adrianlmm4• 11 years ago

and won't work with Chkara

Is your lost.

aravindet2• 11 years ago

This is definitely a problem today, but NAN (https://github.com/nodejs/nan) which is now the recommended way to build native modules, offers a way out. That project provides a stable API to insulate module developers from changes between v8 versions.

Sometime down the line, a NAN-spidermonkey or NAN-chakra project might become feasible.

hackerboos2• 11 years ago

Not Node.js per se but a separate project that ran on the Chkara core and worked hard for cross-compatibility would be more than welcome.

aravindet2• 11 years ago

A node.js fork where you can optionally swap out v8 for chakra: already baked by none other than microsoft.

They hope to merge it back into upstream, that seems possible given the recent history of the Node.js project.

Of course, it is very very unlikely that npm modules with native code work in Node.js/Chakra just yet.

hitekker• 11 years ago

This is the first I've heard that v8 devs don't care for node. Since I am not in the know, are there some sources that detail this issue in depth?

oblio7• 11 years ago

I have a somewhat off topic question: is there anything in the design of Javascript that mandates single-threadedness? Could any Javascript engine implement threads?

I'm asking because I'm wondering if Node.js's evented approach is the only way to do things.

chrisseaton2• 11 years ago

I don't think there is anything preventing JS running shared memory threads. Apart from all the existing code and libraries which aren't thread safe, but that's the case in many languages.

i_s• 11 years ago

There is nothing in the language itself that allows multi-threading. Going forward, they are adding support in the language for the async keyword, similar to F#. Any way to achieve parallelism would have to be from APIs, e.g., like WebWorkers in the browser.

devit• 11 years ago

If you allow threads to share memory arbitrarily you need to add locking to all internal VM structures, which is going to be a significant slowdown.

Also it's not (any longer) considered good practice to have languages that allow mutable memory sharing since that makes software unreliable, so it's not really a good idea.

Without arbitrary memory sharing, multi-threading is already supported with web workers.

DiThi4• 11 years ago

Sharing only typed arrays shouldn't be hard.

netheril96• 11 years ago

Web Worker is very weird in that you have to have a separate file.

Matthias247• 11 years ago

The JVM implementations of Javascript (e.g. Nashorn) support multithreading. Imho it's not a good thing, because all existing Javascript code is written with singlethreading in mind and lots of stuff will break if you use it from multiple threads. Multithreaded code for Nashorn requires the use of JVM synchronization primitives, which are then not supported by other Javascript engines.

jimbobimbo• 11 years ago

My speculation is that before Node stepped into the picture, primary use-case for JS was browser, hence UI manipulation. That usually prompts for a single thread that can update UI, unless you're willing to introduce a lot of mental overhead when dealing with synchronization primitives.

mook• 11 years ago

It used to be possible to write Firefox extensions that used multi-threaded JS; however, like any other language, accessing the DOM was not threadsafe (so you can't have a window be your global object, and therefore they needed to live in separate source files). As JS lacked native support for threading, you also had to be very, very careful and often ended up with less obvious threading issues anyway.

In the last few years SpiderMonkey (Firefox's JS engine) has dropped support for this more and more, and these days you can't anymore. But that's a consequence of the engine implementation, and not the language.

ndesaulniers3• 11 years ago

Mozilla is working on a spec for something called SharedArrayBuffer, which will allow Workers other than the main thread of execution to share memory.

The reason for this is that as soon as you have separate threads sharing memory, it introduces non-determinsism into the mix. When developers use synchronization mechanisms incorrectly, or not at all, this can lead to deadlock between threads.

This must not be allowed to occur on the main thread shared with the rendering engine.

So keep your eyes out for SharedArrayBuffer.

The event loop is very important to the existing language semantics and isn't going anywhere.

ilaksh• 11 years ago

https://www.npmjs.com/package/webworker-threads

treenyc• 11 years ago

No! Javascript the language and thread are not related. If you find a Javascript implemented over JVM like ringojs uses JVM threads to execute JavaScript in parallel. In which case you get both event based within thread, and multi-threaded at the same time.

http://ringojs.org/documentation/ringo_101/

1971genocide• 11 years ago

As a mere mortal - How hard would it be for a day programmer to built something cool like an JavaScript engine ?

I sometimes have crazy thoughts about the world ending.

How hard would it be to built your own javascript engine from scratch ?

jacquesm2• 11 years ago

Building a javascript engine is super simple. But to build one that has performance on par with the current crop will take you - as a single person - a lifetime and by then the state of the art will have moved on.

Locke1689• 11 years ago

The performance is hard, but the bug-for-bug compatibility is what will kill you.

chrisseaton2• 11 years ago

These programs aren't magic. They use the same kind of constructs you use every day to write your programs. They use some different algorithms, but you can look those up in books and in existing engines. People who work on these engines started where you started and there's no reason you can't pick up all the skills over a few years.

AYBABTME• 11 years ago

This is an excellent attitude.

Klathmon5• 11 years ago

It's not as impossible as it sounds.

There are many JS engines which are extremely small compared to the big guys used in browsers. Most of them tend to grab a subset of the language and implement that.

For example, the creators of nginx created their own specialized engine called nginScript that runs JS for their stuff https://www.nginx.com/resources/wiki/nginScript/

There is even a javascript interpreter written in javascript which can be a good starting point to learn a bit how it works https://github.com/jterrace/js.js/

jix• 11 years ago

BeRo did build a javascript engine from scratch on his own: https://github.com/BeRo1985/besen

From the copyright headers he worked on it starting in 2009 and had the first public release in 2014 (actually 2010, see comment below). He certainly worked on other stuff in between too. This is also not a toy implementation. While I have no idea how it compares to state of the art engines, it does feature a whole bunch of optimizations and a JIT compiler.

aurelian15• 11 years ago

Well, the first public release of BESEN was in 2010:

https://delphigl.com/forum/viewtopic.php?f=13&t=9140

whatever_dude4• 11 years ago

The problem with JS engines nowadays isn't as much about the language itself (or its core library), it's more about the absurd amount of optimization it should have to perform well in a varied number of possible setups, and all while the browser is busy doing DOM compositing, loading yet more JS code, etc. Things like JIT are not exactly necessary if you just want your language to "run", but an important part of an optimized system.

To me it seems the past ~5 years of JS engine development have been focused on what kind of optimizations to implement, rather than parsing or implement core library features.

jameshart• 11 years ago

In a world-ending scenario, 'having a working javascript engine' is likely to be surprisingly far down the list of priorities. I think we might actually need a new level on Maslow's hierarchy of needs, just above 'self actualization', for 'lightweight scripting.'

d0m3• 11 years ago

A toy javascript interpreter is quite easy. But a high-performance, production-ready engine is a totally different story.

dubroff• 11 years ago

Anyone have a recommendation for a good place to begin, if I was interested in writing a toy javascript interpreter?

facepalm• 11 years ago

While at university I attended a "learn Scheme" summer course and it was taught by implementing your own Scheme interpreter (in Scheme). It is not that hard to implement a programming language, but making it perform well might be a completely different ballpark.

roddux• 11 years ago

Wait, Edge does better on ES6 coverage than both Chrome and Firefox? Microsoft have seriously stepped up their game, especially seeing as it's now neck and neck for performance with Chrome: http://venturebeat.com/2015/09/10/browser-benchmark-battle-s...

frik4• 11 years ago

No wonder: Microsoft needs "class" syntax in JS, they are a driving for behind TypeScript and ES6. Especially interesting, as Javascript has prototype inheritance. The reason: All of MS code is class-based, and they want it to look similar to C#.

michaelwww• 11 years ago

"JavaScript will never have mandatory types" says Brendan Eich, who doesn't work for Microsoft last I checked, which I mean to say Microsoft is not the driving force behind ES6.

Source: https://channel9.msdn.com/Blogs/Charles/SPLASH-2011-Brendan-... [10:04]

epoch1970• 11 years ago

Developers of large JavaScript codebases have come to realize that class-based OO is exactly what they need. Prototype OO sounds interesting in theory, but in practice it tends to not be what's needed. Projects that use it end up trying to poorly imitate class OO. This wouldn't necessarily be a problem, except it isn't done consistently. There are multiple approaches, some of them which don't mesh well with others. Class-based OO, on the other hand, tends to be much more consistent and well-defined. This consistency improves developer productivity, it keeps the code cleaner, and it allows for greater code reuse between projects. Prototype OO hasn't proven itself in practice, while class OO has again and again.

whatever_dude4• 11 years ago

Yep. They're kicking everyone's asses in ES6 feature coverage. All the more impressive when you consider how they came from behind. http://kangax.github.io/compat-table/es6/

I's almost sad that Edge is not cross-platform.

idibidiart2• 11 years ago

Does it run under Mono?

lobo_tuerto• 11 years ago

It will be, it's mentioned in the article.

hiteshk_msft3• 11 years ago

Engineer on the Chakra team here. As the blog post says, we are definitely interested in going cross-platform. Which platforms would you be interested in seeing first?

arnold_palmur2• 11 years ago

I wonder if Microsoft is actually spearheading the implementation of ES6 in the browser or did they benefit from the timelines of the ES6 specification fortuitously lining up with the development of Edge - or maybe both.

gsnedders5• 11 years ago

As far as one can tell, the move from IE to Edge had much less of an affect on Chakra. (Chakra's codebase is, after all, far newer than IE's!)

stupidcar2• 11 years ago

Not sure what you mean by "lining up with"? The development of ES6/ES2015, and the development of all the browsers and their various JS engines are pretty much ongoing, all the time.

The Edge, Chrome, Firefox and WebKit teams are all working on ES6 compatibility, and releasing new versions pretty frequently. The Edge team are in the lead because they've implemented more features, faster.

Chrome/V8 was actually quite a way behind for a while, although they've caught up quite a bit recently. I believe the situation wrt to V8 within Google was a bit messy for a while, as the original developers (Lars Bak, etc.) were more interested in championing Dart than implementing the latest ES6 features. Eventually, Google had to create a new team, based in Munich, to work on V8.

brianberlin• 11 years ago

weird, feels like that time you see an x across the bar and your like daammn!

oblio7• 11 years ago

Well, historically, when Microsoft was still in competition-mode, Internet Explorer was kicking Netscape's ass with the later versions.

With the first few versions they were playing catch-up, but if I recall correctly, IE 4 and IE 5 actually had more features and better standards compliance than the current Netscape versions, as did IE 6 at its launch.

"IE hell" started once Microsoft won the race.

jayflux• 11 years ago

This is very true. Microsoft are at their best when they're the underdog

bhauer2• 11 years ago

Perhaps. But it's also worth noting that United States vs. Microsoft was coincident with the stagnation in Internet Explorer, with the case starting in 2000, during IE 5's tenure.

For better or for worse, I think the case had a lot to do with Internet Explorer's long pause. I often wonder how Microsoft's browser, its Internet services, and the company as a whole would be today had that case not been undertaken.

wangii• 11 years ago

At that time, MS also had the best online documentation of (D)HTML in MSDN site.

babuskov• 11 years ago

Exactly.

And another, very important thing at that time: IE4/5 was much faster and lightweight than Netspace. I recall using IE all the time just because it take NN forever to start up. The only contender on the speed front was Opera.

jandem• 11 years ago

The next Firefox Nightly build should get 84% on that page, much closer to Edge than Firefox 44 (74%).

I work on SpiderMonkey and I'm super excited about this news. All JS engines have added more-or-less similar performance optimizations but often implemented differently and I'm really interested to see what the Chakra team did. I'd be happy to write a blog post on it next month, if people are interested.

inglor3• 11 years ago

People are definitely interested. Posts about engine architecture are rare and interesting.

teh• 11 years ago

Super interested! I often find technical blog posts like this years later and I'm really grateful to the people who donate their time to the difficult task of writing them.

eiopa• 11 years ago

Super interested!

crudbug• 11 years ago

Scarbutt2• 11 years ago

One would think Firefox would lead here, since the browser is Mozilla's primary product, imagine how much hype and PR Firefox would get if only they were far ahead on ES6.

HalcyonicStorm• 11 years ago

yes please

fenomas4• 11 years ago

Speaking as someone tuning a JS game, I focus on V8 over other engines because there are great articles around that explain in detail what v8 knows how to optimize, what causes functions to deopt, what kicks object property lookups into slow mode, etc. Articles explaining this for SpiderMonkey would be greatly appreciated!

hakcermani• 11 years ago

Totally, and with Typescript 1.7 they have also advanced the node.js game significantly with ES7 features.

megablast• 11 years ago

They skip a lot of stuff supposedly. It is more a subset of javascript than Chrome and Firefox.

jsprogrammer• 11 years ago

Microsoft always steps up its game. It usually just sits around for a while before doing it. (presumably coding)

stefs• 11 years ago

warning: not all of the graphs in the venturebeat article start from 0!

msie• 11 years ago

Yes, that's surprising. Another es6 compat page: https://kangax.github.io/compat-table/es6/ I'm hoping Chrome steps up its game. It's embarrassing.

x5n1• 11 years ago

I can't wait to see what sort of strategic shit they will try to get away this time leveraging "superior" technology.

shams93• 11 years ago

What I'd love to see is webmidi support, it would be rad to be able to do a windows universal app with es6 and create a midi sequencer for my hardware synths, I can do that on chromeos and then package it as an android app on android 5.0+ but I can't do that with windows universal, also can't do that with ios. Webaudio is supported across all three but only google and opera so far support webmidi.

akulbe• 11 years ago

It might perform as fast as Chrome. I certainly wouldn't rank it as stable or memory efficient. It hasn't been, in my experience.

I use Chrome as my primary browser on Linux and OS X. Tried to use Edge as primary on 10, but it's a freaking HOG. I'm using Chrome as primary on 10 now, too.

Can't wait to see what improvements come.

mschuster91• 11 years ago

What in blazes?! Okay MS, that's an impressive step.

I'm waiting for the first ports to Linux or, hell, a native port of IE... given the trend, it's not unreasonable that MS will open source a load of stuff.

nojvek3• 11 years ago

I just want node running on chakra on my linux box. Given MS has a lot of money to make from Azure, I see this happening.

idibidiart2• 11 years ago

Microsoft. Former Evil Empire. Current open source champion. What is not to like? Leadership is everything.

jfoster• 11 years ago

No mention of license. Is it safe to assume it'll be Apache or MIT?

justincormack• 11 years ago

I believe MIT.

abchatra2• 11 years ago

I work for Chakra team and it is going to under MIT license.

proyb2• 11 years ago

Good idea. And please add support for WebMIDI.

supermatt• 11 years ago

This is great news!

japhyr• 11 years ago

We have a bunch of laptops at school running Windows 10 with Edge. Students can't copy and paste into Google Docs while using Edge.

Was this a deliberate choice by Microsoft to steer people away from Google products, or is it something more benign than that?

pimpl• 11 years ago

I had similar problems using Google Docs on Safari too, so I think it’s just a bug on Google’s side.

simoncion4• 11 years ago

AIUI, Safari is the IE6 of the "Modern Web".

thekodols• 11 years ago

If it fails when they paste via right-click menu, it's actually a known issue/design decision on Drive's side. Try using shortcuts instead.

simoncion4• 11 years ago

If it fails when they paste via right-click menu, it's actually a known issue/design decision on Drive's side.

I expect that if this were the problem, OP wouldn't be mentioning it.

When you attempt to use the right-click menu to copy and paste, you get a clearly-worded message box that tells you that you need to use the keyboard shortcuts, and which keyboard shortcuts to use.

simoncion4• 11 years ago

I know a guy who works on core web-dev stuff at Google.

He tells me that Edge is often very quirky in very subtle ways. He's had to spend many, many hours diagnosing, reporting, and working around quirks in Edge. These quirks sometimes get fixed and sometimes do not, but are often not present in Internet Explorer.

ygra• 11 years ago

We have a fairly large-ish JS codebase at work and from what I saw so far is that Edge's JS was never a problem. SVG rendering on the other hand is horribly broken currently for some cases.

That being said, since our JS is generated, it's purely ES5 since it still has to run on IE9. So maybe the weird cases are in the more modern JS parts we don't use.

soared• 11 years ago

This is just how google docs/scheets/slides etc. works on every browser and every OS.

vonklaus• 11 years ago

I find myself hoping Microsoft makes a comeback and they are really doing a lot to win developers which I think is the right move. Obviously, they are a huge platform and developers inherently will be using it but they have taken a lot of great steps like open sourcing this engine as well as other projects.

The Code editor they released is built on Atom Electron and seems more performant than Atom in the few experiences I have had switching between them.

If they can continue to gain trust in the community and improve their UI they could become great again. You can tell they have thought about how to do this. A few years ago now I remember the guys from the IE team did an AMA about the new explorer IIRC it was 10. They talked about cross browser compatibility and wanted developer feedback.

I am not sure if they are actually an "underdog" but I find myself feeling like that, and hoping they can get it together.

zer0defex• 11 years ago

Ditto - and I agree, underdog doesn't quite feel like the right word. It's more like yesterday's champion coming out of retirement to deliver some good old-fashioned ego checks on today's cocky up-and-comers. Either way, it's fun to watch.

meowface• 11 years ago

"Developers developers developers developers" :)

d0m3• 11 years ago

Out of curiosity, why rebuilding a whole new engine rather than using/improving V8?

nojvek3• 11 years ago

Chakra started from a clean slate so they could think about problems differently and not be bogged down by v8 architecture.

spicyj2• 11 years ago

They've already built it, I think before V8 existed or around the same timeframe.

gsnedders5• 11 years ago

It was years later. V8 shipped in 2008, having been in development for (IIRC) three years. Chakra got its first public preview release in 2010, and shipped in 2011—I strongly suspect it started after V8 first shipped.

_wmd• 11 years ago

Why build v8 when SpiderMonkey existed? Why build Chrome when Firefox existed? Ad infinitum

bzbarsky4• 11 years ago

Because you may want to implement things you care about, not necessarily the things the V8 developers care about.

Unless you mean "why write your own engine instead of forking V8", in which case the answer might be that if you have the time to do it, it's easier to become expert on something you created yourself rather than an existing large complex system. And while you're at it you can make sure the system you create is good at solving the problems you mean to solve, which the existing system may not be.

A concrete example of one of the design tradeoffs here: V8 doesn't have an interpreter mode, just several levels of JIT. Every single other browser JS engine does have an interpreter, because it turns out that for cold code (which is most code) that's both faster and less memory-intensive than a JIT. Not to mention allowing your engine to run on hardware for which you haven't created a JIT yet.

cdnsteve• 11 years ago

Well I guess we can all start using ES6, no need to compile to ES5 anymore.

cpeterso• 11 years ago

You will still need to compile to ES5 to support older browsers.

yuhong3• 11 years ago

I was wishing that MS Open Tech could make the other JS engines Windows x64 ABI compliant including SEH for a while now.

caleblloyd• 11 years ago

Fantastic news! Now all we need is for Edge to support Server Sent Events (eventsource)

rakstrooper• 11 years ago

Here's hoping an android port Will be made by microsoft

xxxxc308• 11 years ago

zobzu• 11 years ago

There's no such thing as 'firefox alpha', its 'firefox nightly'

Kinda odd to see when they get the rest right and they're engineers. feels like they dont know firefox o.O

datashovel• 11 years ago

Microsoft is slowly but surely winning me as a fan. Keep doing things that matter, show that you're committed to the open source community, and continue to help push the web forward and I think nothing but good things will come from this.

shmerl• 11 years ago

How about open sourcing the whole browser?

keklord• 11 years ago

Yay I cant wait to test this out

Microsoft Edge's JavaScript engine to go open-source

Related Stories