Understanding CSS and the Modern Web - CSS3 Foundations - page 7

At the time of writing, Microsoft Internet Explorer 10 is available as a preview but hasn't officially been released.

Browser Engines (Layout Engines)
Knowing which engine these browsers support is also useful:

• WebKit ( www.webkit.org/ ) —Both Google Chrome and Apple Safari use this open source engine. Al-
though these browsers use the same engine, they may have implemented it in a slightly different way, so
you shouldn't expect one to render the page exactly the same as the other. Always test in both to make sure.
That said, in most cases, consistency between these browsers is very good. Android Browser also uses We-
bKit, which together with Safari (used on Apple's iPhone, iPad, and iPod products) makes it the most-used
browser engine on mobile devices.
• Gecko ( www.developer.mozilla.org/en/Gecko ) —Mozilla Firefox uses Gecko, another open
source project.
• Presto ( www.opera.com/docs/specs/ ) —Available only as a part of Opera products.
• Trident ( www.en.wikipedia.org/wiki/Trident_(layout_engine) ) —Available only as a
part of Microsoft's products.

These engines are used not only by desktop and mobile browsers but also by other products such as e-mail clients
and word editing software.

What Is Open Source Software?

Open source software is that which is made available for use and modification completely free. This is a great way
to open up a project to everybody and, in turn, enhance the project by having many people improving it at the
same time. CSS3 Foundations uses a few open source projects , and no doubt, you'll come across many on your
own in the future.

Browser Usage Statistics
Although browsers are free to download and use, the web browser market is very much a competitive place. As men-
tioned, vendors are all trying to push the web forward, but they also stand to gain a lot from people using their partic-
ular browser. Some vendors have other products that they want to profit from. The bigger their share of the market,
the more they are able to push these products and services.

Tables 1-1 and 1-2 present the usage statistics provided by www.netmarketshare.com in July 2012 (the time of
writing).

Table 1-1 Desktop Browser Usage
Browser Total Market Share

Internet Explorer 54.02%
Firefox

20.06%