Why are there no real competitors to Javascript?

Question

Perhaps I'm just unaware of the competitors, but it seems when it comes to client-side scripting in the browser and DOM, Javascript is it. I know there's VBScript, but it really isn't even in the same ballpark as JS (not even cross platform, for starters).

I'm just curious about how this came to be. Surely there would be a general desire for a new language to replace Javascript: built from scratch to do all the things Javascript has been bent and moulded into these days (look at the reliance on JS Libraries).

Answer 1

Momentum. JavaScript has been around for 15 or so years, and browser manufacturers have worked for 15 or so years to make it work in their browsers.

If a competitor came along, it would need to really bring something new to the table in order to convince everyone to a) adopt it, b) live with locking out all the users of older browsers like IE7, Firefox 3.0, Chrome 1.0 etc. and c) find replacements for all existing libraries like jQuery, prototype, extJS etc.

In short: we don't need another Standard, let's rather improve JavaScript and build on the rich foundation that already exists instead of starting back from stone age again.

Answer 2

There is! Ones that spring to mind are Flash, ActiveX, and Java... But these all have their drawbacks. Mainly security and integration with the browser/DOM.

Flash and Java live in their own little world, by design (and to address security issues). They can't alter the HTML around them. ActiveX has access to the DOM, but also everything else on your computer.

JavaScript seems to have found a nice balance between flexibility and security, it can trivially interact and alter the pages HTML/CSS, do "safe" networking, has a decent standard library (which has things like JSON, XmlHttpRequest'sih networking, DOM manipulation, and so on). Most importantly, it's available in basically all vaguely-modern browsers, on all platforms, in a consistent manner (compared to CSS)

There are problems with JavaScript, but nothing major. The biggest is the performance. Load a comment page on Digg and watch your CPU usage. Chance are it will be 100% of one CPU core. There are projects to improve this, like SquirrelFish, TraceMonkey, and other strangely named things. But the performance is adequate to do some extremely impressive things (Google Spreadsheet, for example).

Basically, JavaScript is great, and it's drawbacks aren't nearly as big as the other competitors.