In order to ease the development of devices with visual and voice interfaces for PDAs and other handheld devices, the Multimodal Toolkit and Rational Application Developer can be used. By using these products one can minimize the skills and time needed for creating complicated programs that use XHTML+V(XHTML + VOICE) on compatible devices.

XHTML+V is a new technology, that combine XHTML and voice interfaces on small devices, like PDAs and tablets. It is accomplished by combining different web standards, such as ECMAScript, JavaScript, and XML Events. As the technology goes further, the devices tend to be smaller and harder to manipulate, so the XHTML+V technology comes to improve the interactivity of small devices, by using visual and voice interfaces, due to the great processing power that the modern PDAs posses.

XHTML+V supports both voice input and voice output. By predefining the possible input text, and using special software that could recognize the spoken words, the software developers create a viable interface. Also, by implementing speech synthesis software the effect of voice output is received.

Also, the Multimodal Toolkit provides the developer with the ability to create applications that use multimodal access, meaning that they can be manipulated with the stylus, keyboard, and voice in the same time. Imagine yourself that you can write some text in a field, only by speaking it to the device, or that you can choose an element from a menu by reading its name.

With the new technology, the internet access will be much easier for the disabled, by supplying access to the information. The blind people could use XHTML+V in order to easily communicate with the devices, surf on the net and do other useful things that they were unable to do before. Also, by using voice, the impaired get an increased level of mobility and commodity in using the new informational technology.

The Multimodal Technology opens a new era in PDA development, so that now the access to information and the ease of use combine, towards an age of open information.

The PNG format is a format for lossless raster images, which is able to replace such classic formats as TIFF and GIF. It was designed to work mainly with WWW applications; it is robust and provides integrity checks for the file.

It was designed for the purpose of replacing the GIF format, but it also has additional design properties that were added with small effort from the designers. The features that are implemented in PNG and are absent in GIF format include:

1.  Support for images with up to 48 bits per pixel, in True Color. (comparing to 256 colors implemented in the GIF format)
2. Support for grayscale images of up to 16 bits per pixel
3. The addition of full Alpha channel (full transparency masks)
4. Additional image gamma information (it keeps it’s brightness, contrast and other information, so that it could be portable between different machines)
5. Straightforward and easy detection of file corruption.

The development of the PNG standard, together with the development of the specification was supported by the W3C consortium, together with CompuServe Inc, and the main development job was executed by the PNG Development Group.

It was kept in mind that the PNG format should be easily implemented by other developers, so the format is concise and simple. Another strong point of the PNG format is the fact that it is 100% open and doesn’t contain any proprietary code, so that it could be used without attracting excessive attention to the legal problems. Also, by using an algorithm that allows the addition of extensions, it allows for permanent evolution of the format.

The main problem about the PNG format until recent times was browser support. It was supported in Mozilla and Opera browsers, but lacked the required support in Internet Explorer. But after apparition of Internet Explorer 8, it has full support with all the modern browsers.

The increase in the number of devices that can access internet, like digital assistants and phones will require the possibility to access the web regardless the type of the device or the location. The problems of accessibility of the internet resource and the possibility of use by persons with disabilities are also an important characteristic that has to be met in the use of the new technologies.

You can start to learn about the creation of universally accessible web pages, from the Web Accessibility Initiative of the World Wide Web Consortium initiative. The World Wide Web Consortium is an organization that brings together specialists from government, industry and education; the members are preparing standards for users and web developers, which can help to the improvement of web accessibility for the persons that have certain physical difficulties in accessing it.

The cite of the Web Accessibility Initiative (WAI), has information for a large sector of professionals especially in the creation of cites, software and design of internet resources. The cite has a very accessible content, and the information on the cite has a very good structure of access.

The cite has information on Events, News and History; Web Accessibility, Involvement and Information; About the WAI Team; and Sponsors, it also has an informational slide show on the web accessibility initiative. Also the cite has guidelines and techniques, the guidelines have a priority from one to three, that depends on the fact if a web content developer has, is obliged or can realize a particular checkpoint. The guidelines examine the subjects of easy web navigation mechanisms, the best utilization of tables and colors and the applicable alternatives for visual and auditory resources. The guidelines have clear explications and recommendations on how to create an internet cite with an accessible content.

In conclusion the Web Accessibility Initiative of the World Wide Web Consortium initiative, offers and promotes the information needed for the creation of accessible internet content, and helps through the development of technology the disabled persons, and other persons that can have a more effective internet access.

Cascading Style Sheets are an exceptional tool, which gives more control over the design of your site. With CSS, you can precisely specify the location and the appearance of the elements of the web-page, and also create special effects. CSS have multiple advantages in contrast to classic HTML 3, for example you can define different style sheets for different browsers and even use a single style sheet across multiple pages.

A CSS rule is formed of two parts: a selector and one or more declarations, separated by a colon. Also, the declarations must be surrounded by brackets. An example of a CSS rule could be “p {color:red;text-align:center;}”. It means that the color for the text grouped in paragraphs would be red, and that the corresponding text would be aligned in center.

The W3C rules of CSS came in three levels. Level one of CSS (CSS1), published in December 1996, describes the first level of CSS, together with a simple visual formatting model. The second level of CSS (CSS2), published in May 1998, was built upon CSS1 and adds additional support for media-specific style sheets (like support for printers, monitors, etc. ). The CSS mobile profile is still in development.

When you want to use a single style across multiple pages, you can use the external CSS sheets.  In order to do this, you must create a file with “.css” extension, and link it to your page.  If you decide to change a style, you have just to change the CSS file, and the changes would be present in all the pages linked with it.  Also, using an external style sheet ensures the consistency of the style used in all the pages. You could also use embedded CSS style sheets in order to define the style or some elements of style for one single page.

The XSLT and XQuery standards were created by different working groups within W3C. The both share the same data model, type system and function library, and both include Xpath 2.0 as a sub language. XQuery was initially created as a query language that would work with large collections of XML documents; it can also work with individual documents. So, its capabilities overlap with XSLT, which was designed to allow input XML documents to be transformed into XML or other formats.

Anyway, there are great differences between these languages. XSLT was thought of like of a style sheet language, whose primary purpose was to render on screen the XML code, for the commodity of the human eye. XQuery was conceived more like a database query language, similar to SQL. Therefore, XSLT is better handling the documents with more flexible structure, while XQuery better manipulates the relational joints in database.

As usability studies have shown, the XQuery language is easier to learn, especially for people that have previous experience of SQL and other database languages. XQuery is a smaller language, able to create more concise programs. In contrast to XQuery, an orthogonal language, XSLT is more flexible, being a two-language system in which XPath expressions can be nested in XSLT expressions, but not vice-versa. Another strong point of XSLT is that it allows making small changes to a document, by using a coding pattern that involves an identity template, which copies and modifies the selected nodes on the fly. XQuery has no equivalent pattern, but it can appear in the following versions. Another facility that cannot be found in XQuery is any mechanism of polymorphism. The absence of this capability starts to be felt when writing larger programs, or when writing code meant to be reusable in different environments. In this area, XSLT offers the possibility to dynamically match template rules and to override rules using xml:import, that make it possible to write applications with multiple customization layers. The absence of such features in XQuery make it very amenable to static analysis, and also it becomes easier to detect errors in the XQuery code at compile-time.

XSLT 2.0 uses XML syntax, which makes it rather verbose in comparison to XQuery 1.0. Many applications take advantage of this, by using XSLT to read, write and modify style sheets dynamically as a part of a processing pipeline. By contrast, the XQuery code is more suitable for embedding with traditional programming languages, like Java or C#. If necessary, XQuery can be expressed in XML code, which is called XQqueryX. It is very verbose and hard to understand but can be easily processed for example with XSLT style sheets.

Mail marketers often believe that any e-mail that has in its subject or body the words “free” would be filtered. But this is not always true. Even though certain mails, which include different combinations of words containing “free” are filtered, the ISPs could often block your e-mails for other well-known reasons.

As a good example one can use the HTML code. If you use in the e-mails you send incorrect or outdated code, domains such as Hotmail and AOL would surely block it, either send to bulk or junk folders. Even if you see that your email has rendered correctly, and looks just fine to you, Pivotal Veracity, a delivery-monitoring service provider, estimates that nearly every message sent in HTML doesn’t fully comply with the World Wide Web Consortium standards.

Every ISP manipulates differently the e-mails it receives, and therefore the messages that are passed at one destination can be easily blocked at another ISP. Because very many spam mails are sent in HTML format, with heavy use of HTML syntax and formatting errors, in order to trick some of the ISPs, many spam filters will simply delete or send to bulk all the messages that do not correspond to the W3C standards. Well, some infractions are minor and will allow the passage of the mail. An example of such an infraction could be the omission of the tag “alt”, which describes the content in an image tag. Many other faults can send your e-mail the bulk folder.

Pivotal Veracity recently tested a great number of HTML email messages in order to see if they were accepted or rejected by the most popular ISPs. Here are the results if the tests:

• If you use a tracking beacon below the closing HTML tag, your e-mail will be filtered and sent to bulk folder on MSN/Hotmail
• A badly constructed boundary between the text and HTML portions of a multipart e-mail message will send your e-mail at the bulk folder in MSN/Hotmail
• Using hex-encoded characters in URLs (for example by substituting the “%20” code for a space with its hex equivalent) may get the e-mail blocked or into the bulk folder at AOL, CompuServe and MSN/Hotmail.
• Usage of a decoy link that shows one URL in the e-mail but actually redirects you to another URL when clicked will also get the e-mails rejected or sent into the bulk folder at MSN/Hotmail

This material is intended to inform the simple users about the features of the PNG format. So, it will pass over some details like for example the freedom from patents, as this has no connection to the end-user, being more of a concern for the developers.

The PNG format was intended to be used like a substitute for the GIF and TIFF formats. So, it was created with two main ways of usage in view:

1. World Wide Web
2. Image editing

PNG can be widely used for the web, having several advantages over the GIF format: the possibility of transparency by using alpha-channels, gamma-correction (control of image brightness on any platform) and two-dimensional interlacing (a method of progressive display). PNG is also better compressed than GIF, but the difference is small. PNG was intended to be a single-image format, so it cannot contain animation. But there are formats derived from PNG, like MNG and APNG, which support animation.

As PNG’s compression is fully lossless and it supports up to 48-bit images or 16-bit grayscale, manipulating the image would not degrade its quality unlike JPEG. And unlike TIFF, the PNG image is readable in every PNG-supporting application. But JPEG can be compressed to a much smaller file, with the quality close to the original, and the TIFF’s black and white images compressed in Group 4 fax compression are far better than the 1-bit grayscale PNG images.

Being a rester format, like GIF and TIFF, it represents the image like a two-dimensional array of pixels. PNG is not an explicitly vector format, so the images stored in PNG cannot be arbitrarily scaled to any possible size without distortion. In order to be able to do this, one should better use SVG or PostScript. There are also some private extensions the PNG format that add support for the vector information in addition to classic PNG pixel information (for example the extensions from Macromedia Fireworks), but no valid PNG can omit the pixel data.

In 1977 and 1978, two Israeli researchers, Jacob Ziv and Abraham Lempel worked on a set of compression algorithms, which were later named LZ77 and LZ78. Later, in 1983, Terry Welch from Sperry (which later merged with Burroughs to form Unisys) developed a very fast variant of LZ78 called LZW. Welch, together with two IBM researchers, Victor Miller and Mark Wegman, filled for a patent for LZW.

At the same time, Compuserve, specifically Bob Berry, was designing a new algorithm for a compressed image format, where they used the LZW compression, without knowing that LZW algorithms were patented. After the GIF format was already released and popular, CompuServe found out from Unisys that the LZW compression in patented. There was already no way back, so they continued to use LZW, motivated by Unisys’s promises that it would not ask royalties from “pure software developers”. They were instead charging royalties from modem factories, which used LZW.

But at the end of 1993, Unisys started to demand that software developers would pay royalties for them. Of course, the first targeted company was CompuServe. After that, a great panic emerged online, especially on the Usenet newsgroups. Among the panic, a team led by Thomas Boutell was working on creating a new format that would substitute PNG.

Its first name was PBF (Portable Bitmap Format). The first specification contained three-byte signature, chunk numbers rather than chunk names, maximum pixel depth of 8 bits and no specified compression method, but it would afterwards be improved. During a week, the format was discussed, and in the end it came with delta-filtering for improved compression  deflate compression 24-bit support the PNG name itself, internal CRCs, gamma chunk , and 48- and 64-bit support.

After 9 subsequent drafts, the format standards were frozen, with some minor changes along time.  Nowadays, Glenn Randers-Pehrson still keeps some PNGs created at the 9^th Draft. They are still readable by any PNG decoder today

The SMIL Animation was written by the SYMM Working Group, a member of W3C Interaction Domain, in cooperation with the SVG Working Group, a member of W3C Document Formats domain.

The more mathematical but precise definition of animation says that it is a time-based manipulation of a target element (or the manipulation of any attribute of the target element). It’s simply a mapping in time of the different states of the object. This type of mapping is valid for any aspect of timing, as well as animation-specific semantics.

The simplest way to describe an animation can be made by splitting it in three parts: the beginning of the animation, the animation function and the duration of the animation. The beginning of the animation is simply its initial state. The animation function is simply a definition of the way the initial object will be distorted. And the duration of the animation means the time that the animation function will influence the initial state object.

During the time of implementation, the animation function is evaluated as required, being continuous in time and therefore usable at any frame rate required for the rendering system. On the other hand, the syntax of this function is independent of the previous model, and can be implemented in many possible ways, either purely algorithmic, or partially algorithmic. Anyway, the animation is represented as a function of time. The total range of manipulation the animation can do with the object is virtually infinite. They can either override the values of an attribute, or add to the base value an attribute. The animations that add to the underlying value are called “addictive animations” and the animations that override the underlying value are called “non-additive animations”

Usually the SMIL animation is used together with vector graphics (typically SVG) and XHTML mark-up language, together with CSS. Using SMIL with pixel graphics would mean a lot of computations made by the PC, and therefore a loss in productivity.

SharePoint is a heavy CSS user, which could be both seen as a curse and a blessing in the same time.  Because about all of the SharePoint UI is hard coded in the site definitions, CSS is the best way to operate the changes on the site.

A Share Point 2003 portal contains 7 different style sheets, which make up a total of 7403 lines of code and 1227 style sheet statements. Of these seven, four are hardly ever needed to be edited (menu.css, owsmac.css, owsnocr.css, paystub.css).

The other three style sheets are easy:

1. sps.css : Share Point 2003 Portal style sheet
2. OWS.css: SharePoint 2003 Portal style sheet and Windows SharePoint Services style sheet.
3. OWSPERS.css: Share Point 2003 Portal Personal Sites style sheet. (Also known as My Sites style sheet)
4. OWSPERS.css is a combination of a copy of SPS.css and OWS.css with a few tweaks. There is a way to condense the style statements in OWSPERS.css to something more manageable and without so much repetition.

SPS.css and OWS.css have some style selectors that are repeated in each. In some cases, the styles are not connected, but in others one can possibly override the second and therefore create a lot of confusion and frustration. Also, the styles may share the same selector, but have different properties in the declaration.

When opening a page, the following style sheets are pulled, in order: 1) OWS.css; 2) MENU.css; 3) SPS.css. When opening a WSS site, the file OWS.css is pulled, and afterwards the theme style sheet.

It is very important to understand the order in which the style sheets are used, because the last property that is used in a declaration of a selector will be used on the page. So, for example if you want to change something in a page, you may simply modify the theme, and therefore the settings contained in that theme style sheet would override the settings from the included CSS.