http://www.w3help.org/zh-cn/kb/001
IE 系列的“混杂模式”，将浏览器的行为冻结在了 IE5.5 这个版本，虽然 IE 各版本的混杂模式也略有区别5，但它们的本意都是向后兼容。
IE8 重新定义了“标准模式”，再次增强了对标准规范的支持，同时为了保持对 IE7 的兼容，IE8 增加了一种工作模式：“接近标准模式”。于是，IE8 的工作模式就分成了三种：“标准模式”、“接近标准模式”和“混杂模式”6。
附录: 一些常见的 doctype
| doctype | IE6
Opera 7.0 | IE7
Opera 7.1 | IE8
Opera 9.5 | Opera 9.0 | Firefox
Chrome
Safari
Opera 10 |
|---|
| <!DOCTYPE html> (推荐！) |
A |
A |
S |
S |
S |
|---|
| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> |
Q |
Q |
Q |
Q |
Q |
|---|
| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN"> |
A |
A |
A |
S |
S |
|---|
| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN" "http://www.w3.org/TR/html4/strict.dtd"> |
A |
A |
A |
S |
S |
|---|
| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"> |
A |
A |
A |
S |
S |
|---|
| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> |
A |
A |
A |
S |
S |
|---|
| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> |
Q |
Q |
Q |
Q |
Q |
|---|
| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> |
A |
A |
A |
Q |
Q |
|---|
| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> |
Q |
Q |
Q |
Q |
Q |
|---|
| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> |
A |
A |
A |
A |
A |
|---|
| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/1999/REC-html401-19991224/loose.dtd"> |
A |
A |
A |
A |
A |
|---|
| <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> |
A |
A |
S |
S |
S |
|---|
| <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN" "http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd"> |
A |
A |
S |
S |
S |
|---|
| <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> |
A |
A |
S |
S |
S |
|---|
| <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> |
A |
A |
A |
A |
A |
|---|
| <!DOCTYPE HTML PUBLIC "ISO/IEC 15445:1999//DTD HyperText Markup Language//EN"> |
A |
A |
S |
S |
S |
|---|
| <!DOCTYPE HTML PUBLIC "ISO/IEC 15445:2000//DTD HTML//EN"> |
Q |
Q |
Q |
Q |
S |
|---|
| <!DOCTYPE HTML PUBLIC "ISO/IEC 15445:1999//DTD HTML//EN"> |
Q |
Q |
Q |
Q |
S
|
|---|