History of JavaScript: Part 2

2010-05-31 00:00:00 +0100 by Alex R. Young

This article is part 2 of our History of JavaScript series. Last week we
looked at Brendan Eich, who created JavaScript for Netscape.
Subsequently, the first edition of the ECMA-262 specification was
accepted in 1997.


Once ECMAScript was standardised, JavaScript became Netscape's dialect
of ECMAScript. Other popular dialects are ActionScript and JScript (used
in Internet Explorer). A dialect can be said to be ECMA-262 compliant if
it satisfies the specification, and will often include proprietary
extensions that suit the context of the implementation.

Browser Wars

As I mentioned last week, Microsoft introduced JScript as a reaction to
Netscape's JavaScript. Microsoft kept JScript largely compatible, which
helped JavaScript gain popularity.

It sounds funny now, but some unloved proprietary features like the
blink tag were introduced during the browser wars. More
serious features were also introduced, but the usefulness of these
wasn't always apparent at the time.

A good example is XMLHttpRequest. Microsoft created the concept behind
it, although ActiveX was used. This shipped with Internet Explorer 5.0
in 1999. It wasn't until 2006 that the W3C published a working draft for
XMLHttpRequest itself.

Another proprietary feature introduced by Microsoft was the
innerHTML property. Netscape added support for this
property in May 2000 due to its popularity and requests from the

Document Object Model

With proprietary tags and properties like innerHTML, it's
not surprising that the development of the Document Object Model (DOM)
was central to the browser wars. JavaScript's power in client-side web
code is crippled without a clean API for manipulating elements, and
Microsoft and Netscape had a few false starts before standardisation.

Level 0 DOM was implemented by Netscape in JavaScript for Netscape 2.
Even modern browsers support it, despite its questionable usefulness.
Microsoft copied it for Internet Explorer 3.

If you started learning web development in the 90s, you'll probably be
familiar with the basic usage of DOM Level 0:

// Return all the forms on the page:

// Return the first image:

// Changing a property:
document.images[0].src = '/images/rollover.gif'

The World Wide Web Consortium (W3C) was founded in 1994, and had already
helped standardise JavaScript through ECMAScript. In late 1998 the
recommendation for DOM Level 1 was announced. Internet Explorer 5.0
shipped with partial support. It wasn't until 2000 that DOM Level 2 was
published and we finally had getElementById and an event

In some ways this was already too late. Microsoft had its own event
model, which is still used today. If you've been following our Let's
Make A Framework
series you should have seen example code for Microsoft
event handling.


Meanwhile, as of version 4, Internet Explorer had been integrated into
Windows. This was the point at which Netscape's market share started to
suffer. Eventually it became clear that Microsoft's strategy was
potentially anti-competitive, and this prompted the antitrust case in

The case didn't help Netscape -- Internet Explorer 6 became the dominant
browser. This arguably ended an era of rapid innovation on the web, and
it wasn't until the excitement over Web 2.0 that IE started to seriously
lose ground.

Part 3

Next week I'll continue this series, exploring the years leading up to
the Web 2.0 revolution.