之前一直在学习XHTML，现在准备着手HTML5，有一些非技术性的疑问，想请明白的人讲解一下：
1.我在一本书上曾经看到过，W3C在发布XHTML标准时宣称将来不再开发HTML，而是专注于XHTML，朝着XML方向发展，那么这个HTML5是处于一个什么地位呢？W3C是不是放弃了原来的路线呢？
2.HTML5不是基于SGML或XML，这是怎么回事儿？未来发展方向不是XML了吗？是不是路线偏离了呢？
这两个方向性的问题还请高手释疑。
回复讨论(解决方案)
第一个问题你要去问W3C
“结构与表现分离”这一思想还会不会一直延续下去？HTML5依然推崇这一原则吗？
1、书上说的不一定准
2、html5兼容以前的html和xhtml。根本没有xml那样的严格验证
文档头部写html>就可以了
ie6不认识html5
1、书上说的不一定准
2、html5兼容以前的html和xhtml。根本没有xml那样的严格验证
文档头部写html>就可以了
关键是W3C也在进行XHTML2.0的开发，我看网站上有关于XHTML2.0和HTML5.0之间竞争的一些讨论，但基本都是07、08年的，貌似XHTML2.0最近已经销声匿迹了，我就是不明白WEB标准的发展方向是什么，W3C是不是没落了啊，还有就是HTML5的基本理念有哪些呢？
比如，XHTML的给我们带来了“结构与表现分离”的思想以及XML的发展方向，那么HTML5呢？依然坚守这一思想和大的方向吗？
ie6不认识html5
恩 所有的浏览器都不是完全“认识”html5，呵呵
1、书上说的不一定准
2、html5兼容以前的html和xhtml。根本没有xml那样的严格验证
文档头部写html>就可以了
另外，html5还遵循xhtml中要求的那些严格的语法吗？比如标签必须闭合、正确嵌套之类的，这些是未来的方向吗？
参考 http://blog.sina.com.cn/u/2760399482
html5我理解的并不是html而是xhtml css3 canvas等等一系列的集合
html5我理解的并不是html而是xhtml css3 canvas等等一系列的集合
html5不是xhtml和css3等的集合吧，它是独立的啊
html5增加了 head/foot 等标签，就是为了语义化。
引用 4 楼 的回复:
ie6不认识html5
恩 所有的浏览器都不是完全“认识”html5，呵呵
虽然ie6-ie8不支持html5但是只要加入一个非常简单的js文件就可以使html5的新元素在ie的早期版本中显示。
貌似最近回复的有点偏离我的主题。。。
1998年，W3C决定不再继续推进HTML,他们相信，xml是未来。因此，html规范4.0.1版就冻结了，并且发布了一个新的名为xhtml的规范，它是html的一个xml版本，需要一些xml语法规则，如用引号括起属性，结束某些在其他情况下是自结束的标记等，增加了两种内容（实际上是三种，如果你关注html frame）有一种xhtml过渡形式，来帮助人们转向xhtml严格形式的黄金标准。
这一切进展顺利，它鼓励一代开发者考虑有效的，结构良好的代码。针对xhtml2.0规范的工作随后开始了，这对该语言是一次革命性的改变，因为它为了变得更有逻辑性和更好设计而打破了向后兼容。
然而，opera的一小部分群众，不相信xml是所有web开发者的未来。这些人开展了额外的工作，以证明扩展html形式且不必违反向后兼容的规范是可行的。该规范最终变成了web forms 2.0，随后加入到html5中。
2006年，w3c承认他们在期待该领域迁移到xml方面过于乐观。
重新开始工作的html工作组通过投票，使用whatwg的web applications规范作为html新版本的基础。
2009年，W3C停止了关于xhtml2.0的工作，并且将资源转向html，由此，html5显然赢得了这场理论之战。
IE6已经成为历史了，HTML5才是Web的未来，浏览器只会是越来越进步，所以，离开IE6、7、8的日子是指日可待了
IE6已经成为历史了，HTML5才是Web的未来，浏览器只会是越来越进步，所以，离开IE6、7、8的日子是指日可待了
目前是HTML5的天下，这是事实，但是WEB的未来不是XML吗？从XHTML过渡到XML的路线不好吗？我感觉XML在存储 和交换信息方面的功能比较强大哦~
w3c就是统一web标准，结构与样式分离以后肯定会延续下去啦！xhtml1.0就是html的标准！以后标准浏览器都可以解析标准代码的！
w3c就是统一web标准，结构与样式分离以后肯定会延续下去啦！xhtml1.0就是html的标准！以后标准浏览器都可以解析标准代码的！
现在W3C还有XHTML工作组，在进行XHTML2.0的标准化工作，这个本来就是W3C对未来路线的规划（即有HTML??XHTML??XML），但是谁料HTML5半路杀了出来，并且在各大浏览器的拥戴下不得不被W3C采纳为标准，成为当今的主流，这在一定程度上影响了W3C的路线，并直接导致XHTML2.0无人问津的悲惨现状，不知道WEB标准的未来方向会不会因为HTML5而发生改变。
这一切进展顺利，它鼓励一代开发者考虑有效的，结构良好的代码。针对xhtml2.0规范的工作随后开始了，这对该语言是一次革命性的改变，因为它为了变得更有逻辑性和更好设计而打破了向后兼容。
然而，opera的一小部分群众，不相信xml是所有web开发者的未来。这些人开展了额外的工作，以证明扩展html形式且不必违反向后兼容的规范是可行的。该规范最终变成了web forms 2.0，随后加入到htm……
非常感谢啊，一直想找关于html5和xhtml2.0之争的历史细节，终于找到了~
For its first five years (1990-1995), HTML went through a number of revisions and experienced a number of extensions, primarily hosted first at CERN, and then at the IETF.
With the creation of the W3C, HTML's development changed venue again. A first abortive attempt at extending HTML in 1995 known as HTML 3.0 then made way to a more pragmatic approach known as HTML 3.2, which was completed in 1997. HTML4 quickly followed later that same year.
The following year, the W3C membership decided to stop evolving HTML and instead begin work on an XML-based equivalent, called XHTML. This effort started with a reformulation of HTML4 in XML, known as XHTML 1.0, which added no new features except the new serialization, and which was completed in 2000. After XHTML 1.0, the W3C's focus turned to making it easier for other working groups to extend XHTML, under the banner of XHTML Modularization. In parallel with this, the W3C also worked on a new language that was not compatible with the earlier HTML and XHTML languages, calling it XHTML2.
Around the time that HTML's evolution was stopped in 1998, parts of the API for HTML developed by browser vendors were specified and published under the name DOM Level 1 (in 1998) and DOM Level 2 Core and DOM Level 2 HTML (starting in 2000 and culminating in 2003). These efforts then petered out, with some DOM Level 3 specifications published in 2004 but the working group being closed before all the Level 3 drafts were completed.
In 2003, the publication of XForms, a technology which was positioned as the next generation of Web forms, sparked a renewed interest in evolving HTML itself, rather than finding replacements for it. This interest was borne from the realization that XML's deployment as a Web technology was limited to entirely new technologies (like RSS and later Atom), rather than as a replacement for existing deployed technologies (like HTML).
A proof of concept to show that it was possible to extend HTML4's forms to provide many of the features that XForms 1.0 introduced, without requiring browsers to implement rendering engines that were incompatible with existing HTML Web pages, was the first result of this renewed interest. At this early stage, while the draft was already publicly available, and input was already being solicited from all sources, the specification was only under Opera Software's copyright.
The idea that HTML's evolution should be reopened was tested at a W3C workshop in 2004, where some of the principles that underlie the HTML5 work (described below), as well as the aforementioned early draft proposal covering just forms-related features, were presented to the W3C jointly by Mozilla and Opera. The proposal was rejected on the grounds that the proposal conflicted with the previously chosen direction for the Web's evolution; the W3C staff and membership voted to continue developing XML-based replacements instead.
Shortly thereafter, Apple, Mozilla, and Opera jointly announced their intent to continue working on the effort under the umbrella of a new venue called the WHATWG. A public mailing list was created, and the draft was moved to the WHATWG site. The copyright was subsequently amended to be jointly owned by all three vendors, and to allow reuse of the specification.
The WHATWG was based on several core principles, in particular that technologies need to be backwards compatible, that specifications and implementations need to match even if this means changing the specification rather than the implementations, and that specifications need to be detailed enough that implementations can achieve complete interoperability without reverse-engineering each other.
The latter requirement in particular required that the scope of the HTML5 specification include what had previously been specified in three separate documents: HTML4, XHTML1, and DOM2 HTML. It also meant including significantly more detail than had previously been considered the norm.
In 2006, the W3C indicated an interest to participate in the development of HTML5 after all, and in 2007 formed a working group chartered to work with the WHATWG on the development of the HTML5 specification. Apple, Mozilla, and Opera allowed the W3C to publish the specification under the W3C copyright, while keeping a version with the less restrictive license on the WHATWG site.
Since then, both groups have been working together.
The HTML specification published by the WHATWG is not identical to this specification. At the time of this publication, the main differences were that the WHATWG version included features not included in this W3C version: some features have been omitted, but may be considered for future revisions of HTML beyond HTML5; and other features were omitted because at the W3C they are published as separate specifications.
A separate document has been published by the W3C HTML working group to document the differences between the HTML specified in this document and the language described in the HTML4 specification. [HTMLDIFF]
我也找到了一些，摘自W3C网站上HTML5最新working draft中关于history的叙述（http://www.w3.org/TR/html5/introduction.html#history-1），有需要的看一看吧，谢谢楼上朋友们的回复~
