Know XMLWritten by Pawan Bangar,Birbals,India
Introduction to XML XML--- extensible markup Language --- is an exciting development in web technology. It is youngest and most comprehensive of markup Language. (Markup refers to any thing on a document that adds special meaning to a particular text; for example, bold text is a form of markup). This language got name Extensible Markup Language from characteristic that is not restricted to fixed set of tags, as is HTML (Hypertext Markup Language). An XML user creates his own tags according to need. A tag is a sequence of characters in a markup language used to provide information, such as formatting specifications, about a document. Markup languages are roughly classified into three types: •Stylistic ----- defines character presentation; for example bold, italics, underline, font etc. •Structural ----- define structure of document as for heading and paragraph. •Semantic ----- informs us about content of data, like giving a title. SGML (Standardised Generalised Markup Language) is mother of all markup languages and has been in existence since late 1960s. In 1986 it becomes an international standard for defining markup languages. It is used to create other languages, including HTML, which is very popular for its use on web. HTML was made by Tim Berners Lee in 1991. While on one hand SGML is very effective but complex, on other, HTML is very easy but limited to a fixed set of tags. This situation raised need for a language that was as effective as SGML and at same time as simple as HTML. This gap has now been filled by XML. The development of XML started in 1996, when a team led by Jon Bosak of sun Microsystems began work on a project for remoulding and cutting inessential parts of SGML. They took best of SGML, guided by experience with HTML, and produced something that was no powerful, but much simpler to use. The World Wide Web Consortium also contributes to creation and development of standard for XML. The specifications for XML were laid down in just 26 pages, compared to 500+ page specifications that define SGML. Although, XML looks like HTML, there is a world of a difference. While HTML specifies what each tag and attribute means and how text define by it will look in a browser, XML uses tag only to delimit pieces of data, and leaves interpretation of data completely to application that reads it. For example, if we see "" in an XML file, it may or may not mean bold (as in HTML) ---- it may mean 'book', ‘bank' or anything else specified by programmer. HTML is only a presentation technology ----it carries no description of content held within its tags ----whereas in XML a programmer can describe text in its own tag. Moreover we can specify importance of a tag in XML so that a hierarchy of data can be represented, which is not possible in HTML.
| | That Darned Old Internet Gateway!Written by David Morse
WARNING! WARNING! DANGER! DANGER! This is just how I felt after recent experiences of helping a friend of mine get his new wireless router working. I was talking him through some of settings on phone while looking at my router, which is exact same model.Now I am not new to computers or networking but I must say that Windows XP still throws me now and then. My friend starting reading his screen to me and mentioned Internet Gateway when he went into his Windows XP Networking Connections. There was a red flag! I told him hooooold on! Stop! Now what did you say again? He said in his Network connections he saw an icon for Internet Gateway. My immediate thought was somehow he had managed to turn on Internet Connection Sharing or ICS. I bopped on over to my new laptop, running XP Professional and…BAM! I had exact same thing on mine. I hadn’t seen this cute little icon before. Maybe I just hadn’t “just right” opportunity of noticing it before? Who knows… In my infinite wisdom (Of not knowing what this little mysterious icon would do for o me.), I decided it must be ICS and I didn’t want that, so I right-clicked and disabled sucka! Well, not a swift move for me. It did indeed disable it. The icon went away and so did my whole home network’s Internet connection. DOH! I tried to simply enable it again, but as I said, icon was now gone. There was nothing to click to enable. I went through everything I could think of but none of my computers could get out to Internet though router. I use a cable modem so I plugged a computer directly into it, rebooted computer and YES, access once again. So I knew problem had to lie with router. It seems somehow I had managed to turn off some portion of my router by just disabling Internet Gateway from my XP Pro. After fumbling around for hours shutting everything down, resetting router with hardware reset button, reconfiguring all router settings I still could not get it to work again. I wondered if XP had actually shut down router’s WAN port. I finally broke down and called Linksys technical support. I first tried their online knowledgebase, which wasn’t working, online live chat, which nobody answered, and searching net for answers. After being on hold for quite some time, a tech finally answered and she was very polite and helpful. I knew she was going to walk me through shutting down everything and resetting and I told her I had already done this but would be willing to do whatever she suggests at this point. Well I’m glad I did. I did in fact already do everything she was having me do, but missed sequence of steps. So let that be a lesson, do not think you’ve exhausted all simple fixes until tech tells you that you have. :)
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