为什么 javascript 是浏览器中唯一的客户端脚本语言？

为什么浏览器不支持 Python 脚本代替 Javascript 呢？或者更通用的脚本语言？Javascript 是唯一跨浏览器实现的原因是什么？毕竟，script 标签支持指定所使用的脚本语言。

(我知道 IE 中支持 VBScript，但它似乎已经过时了。)

29218 次浏览
小开

Because JavaScript is what every other browser supported, and browser vendors had two main priorities:

  1. Making sure existing webpages worked (which requires JavaScript)
  2. Letting authors do user visible things in their browser that they couldn't do in other browsers (changing programming language would be entirely hidden from users, except when it broke).
小开
最佳答案

Well, Google is trying to buck that trend with Dart. The community hasn't been entirely receptive to the idea; either.

Google proposed adding multiple VM support for Webkit which didn't go down very well.

One particular comment summed it up nicely as to why there has been some resistance to that:

In this case the feature is exposing additional programming languages to the web, something without any real benefit to anyone other than fans of the current "most awesome" language (not too long ago that might have been Go, a year or so ago this would have been ruby, before than python, i recall i brief surge in haskell popularity not that long ago as well, Lua has been on the verges for a long time, in this case it's Dart -- who's to say there won't be a completely different language in vogue in 6 months?), but as a cost it fragments the web and adds a substantial additional maintenance burden -- just maintaining the v8 and jsc bindings isn't trivial and they're for the same language.

The issue here isn't "can we make multiple vms live in webkit" it's "can we expose multiple languages to the web", to the former i say obviously as we already do, to the latter I say that we don't want to.

Unless we want to turn webkit into the engine that everyone hates because of all its unique "features" that break the open web, a la certain browsers in the late 90s.

CoffeeScript is another example of an emerging client-side scripting language. However, rather than support another virtual machine in a browser (as Google is trying to do with Dart), it compiles to JavaScript. There are several other "compile X to JavaScript" that do that as well. emscripten is a good example of compiling LLVM to JavaScript.

So there are plenty of other client languages; they just all use JavaScript as an intermediate. I'd argue that should be what Dart does as well, though they have some room to improve.

小开

Internet Explorer supports any Windows Script Engine, so you can make it support any language that has been implemented as one, or write your own.


提交答案