Web Technologies

Introduction

When you want to provide services to customers over the internet, you are faced with a confusing array of options. The landscape is changing rapidly, and you have to make the call on which technology is the most appropriate for you. What are the options? What are the pros and cons of each? How do you decide which one you want? Here's the Dummies Guide to internet technology.

Standard HTML Web Pages

Starting with the humble HTML web page, you would think that you were on safe ground. Then people start mentioning W3C standards, XHTML, accessibility, cross browser compatibility and stylesheets (CSS). Anything other than the simplest page demands that you use javascript. So what are these things, and why do you need them?

W3C standards

The World Wide Web Consortium (W3C) is an organisation that creates standards and guidelines for the web, and most browser vendors produce 'standards' browsers that follow these (Firefox, Opera, Safari). Microsoft's Internet Explorer is the notable exception, unfortunately, but IE is improving its standards support with each release. It makes absolute sense to follow these standards rather than support a particular vendor's browser to the detriment of all others. Standards support is getting better, so the browsers will support your web pages better as time progresses. When there is a browser bug, it isn't unusual for people to demand that you, as author of the web page, fix it. It is a misunderstanding of how the web works, and especially how it will work over the next few years. You don't support a browser, the browser supports standards, which you adhere to. If the browser has a bug, and there isn't an elegant way to work around the problem, then it is up to the browser vendor to fix it. "Don't we support IE any more?" is a question that highlights a fundamental misunderstanding of the internet.

XHTML

So you know web pages are written in HTML. Well, now we have XHTML, and the benefit of this over HTML is that its far better defined, and can be described by an XML schema (hence the X prefix). The upshot of this is that browsers find it far easier to interpret, and therefore next generation browsers should have far better, more consistent support for XHTML web pages. As a result, cross-browser compitbility should improve, lessening development and maintenance overheads that we currently incur ensuring that our web pages work on all browsers. It takes less processing to read XHTML, so it works far better on browsers that run on mobile phones or PDA's. Basically, if your site is XHTML, you are expanding your user base and future-proofing your website.

Cascading Style Sheets (CSS)

Cascading Style Sheets (CSS) allow you to seperate your web page's document structure and data from its presentation data. You create a central style sheet that gives you the ability to make global changes to the look and feel of your website. If you want all buttons to be red instead of blue, its on quick change to the CSS file. If you want to dynamically rebrand your site depending who is viewing it, you can do that too. Although it isn't the work of a moment to build CSS that works across all browsers, once it is in place, writing brand-complient web pages becomes a doddle, as you just have to write the correct document structure, and the page will automatically conform to brand guidelines. Investing in CSS, seperating out the presentation information, will save you when it comes to development and maintenance and rebranding.

Accessibility

Accessibility of web pages means writing them in such a way as to allow everyone to access them. People who have difficulty reading a monitor should be able to use a screen-reader to read your web pages and give a good user experience. Turning images off should not compromise the user experience. Using a different browser or device should not make the site inaccessible. And more controversially, turning off javascript should not deny the user access to the site.
Following web standards makes your site accessible, see the guidelines on the W3C site.
The basic motivation for making your website accessible is to make it available to the widest possible audience, but more crucially, not to discriminate against anyone. If you do discriminate against somebody by not making your website accessible, you leave your company open to legal action. Motivation enough, I think you'll agree...

Flash, Flex and Rich Internet Applications (RIA)

Adobe's (formerly Macromedia) Flash player allows you to provide a richer graphical experience using the FlashPlayer browser plugin, and also allows you to stream music and video. The term RIA (Rich Internet Application) refers to a browser based application that takes on more of the UI processing at the client side, therefore running something approaching a desktop application within the browser. However, most of the data and state information is still held at server side and is accessed via the internet. Adobe's Flex offering provides a toolkit to enable development of RIAs.

Smart Clients

If we take this transfer of responsibility to its natural conclusion, Smart Clients are applications that are installed on the user's desktop with access to local resources (memory, disk, database etc), and merely accesses data from the internet when necessary. This is where the industry is heading in the next few years.

Web Services

If you want to access data in a standards compliant way across the internet from your website, RIA or Smart Client, then you will be needing Web Services. Web Services are a standards complient way to offer services securely over the internet. The W3C have produced the WS-* standards, and various implementations of these include Microsoft's WSE2, WSE3 and Indigo and Apache's Java based Axis.