XML. Extensible Markup Language (XML) takes Web document formatting a giant leap forward. XML is a new markup language specification developed by the W3C (the World Wide Web Consortium). XML is a markup language like HTML, but it has very different purposes. Whereas the purpose of HTML is to control the “look and feel” and display of data on the Web page, XML is designed to describe data and information.

　　XML(可扩展标示语言)。XML使网络文件格式化发生了一次巨大的飞跃。XML是由万维网联合会开发的一种新型置标语言规范。XML是像HTML一样的一种置标语言，但是它又有非常不同的目的。XML是用于描述数据和信息,而HTML的目的是控制"表现与感觉" 并将数据在网页上显示。

　　For instance, if you want to send a patient’s medical record—including diagnosis, personal identity, medical history information, and any doctor’s notes—from a database in Boston to a hospital in New York over the Web, it would be impossible using HTML. However, with XML, these rich documents (database records) for patients could be easily sent over the Web and displayed.

　　比如，如果你想要把一个病人的病历卡——包括诊断、个人身份、病史信息和任何医生笔记——通过网络从一个在波士顿的数据库发送到位于纽约的一所医院，使用HTML是不可能的。然而，使用XML，这些有关病人的富文件(数据库记录)可以容易通过网络发送并显示。

　　XML is “extensible,” which means the tags used to describe and display data are defined by the user, whereas in HTML the tags are limited and predefined. XML can also transform information into new formats, such as by importing information from a database and displaying it as a table. With XML, information can be analyzed and displayed selectively, making it a more powerful alternative to HTML. This means that business firms, or entire industries, can describe all of their invoices, accounts payable, payroll records, and financial information using a Web-compatible markup language. Once described, these business documents can be stored on intranet Web servers and shared throughout the corporation.

　　XML是 "可扩展的",意味着用于描述并显示数据的标签被使用者定义,而在HTML中标签是有限制的，而且是预先定义的。XML也能把信息转变成新的格式,例如从一个数据库输入信息并显示为一张表格。使用XML，数据能被有选择性地分析且显示,使它成为比HTML更有力的可选方案。这意味着商业公司,或整个行业,全部能使用与网络兼容的置标语言通过发票、可支付帐户、薪资记录和财政信息来描述。一旦完成描述,这些商业文件可以被储存在内联网网络服务器上并在整个公司共享。

　　XML is not yet a replacement for HTML. Currently, XML is fully supported only by Microsoft’s Internet Explorer 5, and is not supported by Netscape (although this may change). Whether XML eventually supplants HTML as the standard Web formatting specification depends a lot on whether it is supported by future Web browsers. Currently, XML and HTML work side by side on the same Web pages. HTML is used to define how information should be formatted, and XML is being used to describe the data itself.

　　XML仍然不能替换HTML。当前，只有微软的Internet Explorer 5完全支持XML,而Netscape(网景公司)不支持 (虽然这种现象可能改变)。XML能否最终替代HTML作为标准的网络格式规范，在很大程度上仰赖于将来的网络浏览器是否支持它。目前,XML和HTML在相同的网页上并肩工作。HTML用来定义应该如何格式化信息，而XML用来描述数据它本身。

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