Web Standards, xhtml and css
What are web standards?
Although probably of not much interest to the majority of web site owners, 'Web Standards' are a very important topic indeed. What you should know is that web sites not developed and structured to follow the standards set out by W3C will not work or display correctly in all browsers on all platforms. We test all our sites on the latest batch of browsers, so you and your company can be sure that your customers can see your presence on-line, exactly the way you want them to.
Accessibility and Usability
What are Cascading Style Sheets?
Cascading Style Sheets (CSS) save a lot of bandwidth, vastly reducing the size of your files when compared to old-style code. With style sheets, your sites load faster. One small CSS document can style an entire domain; and when it's time to redesign, you can execute site-wide changes in just minutes instead of days.
Style sheets bring genuine leading and sophisticated margination to the web, easing our readers' eyestrain while allowing us to take control of negative space (negative space is the space between objects or parts of an object, or around it) we take for granted in other media. Style sheets offer exciting new possibilities, from absolute positioning, to interactive manipulation of text and images. They also allow us to create sophisticated layouts while doing no harm to the underlying structure of our documents - ensuring that search engines (as well as hand-held devices and web phones) can 'understand' our pages as easily as our readers do.
What is XHTML anyway?
XHTML is HTML written according to the XML rules of well-formedness. To understand XHTML, we therefore have to understand XML. There have been many articles written on this subject, so a short summary should be enough:
XML is the Extensible Markup Language. It improves the functionality of the Web by letting you identify your information in a more accurate, flexible and adaptable way. It is extensible because it is not a fixed format like HTML (which is a single, predefined markup language). Instead, XML is actually a metalanguage - a language for describing other languages - which lets you design your own markup languages for limitless different types of documents. XML can do this because it's written in SGML, the international standard metalanguage for text document markup (ISO 8879).
In contrast, HTML is a much more rigidly defined markup language where your tags have to adhere to a syntax to make sure browsers understand you. Nonetheless, the open character of XML allows us to treat HTML documents as XML documents with the specific purpose of being shown by a web browser. However, the old standards of HTML are not completely XML compatible. For instance, using a </P> at the end of each paragraph is not required in HTML, it is optional. Web browsers don't care if it's there because they're programmed not to, but XML parsers are much stricter and will tell you that your HTML document is not well-formed XML.
To bridge the gap between the two, XHTML was developed. XHTML is a stricter form of HTML and as such is a subset of XML.
The headers you sometimes see along with XHTML code declare what exactly the rules are, for instance, that <a> is an anchor. In XML you can declare your own rules.
XHTML is significantly better than HTML, as it encourages good practice. Where it doesn't allow things that HTML does, there is probably a good reason... for instance not using target="_blank". These things then in turn impact on the sites accessibility, consistency and ranking performance in the search engines.