what is RSS

RSS是一種用於網上新聞頻道、博客（weblogs）和其他Web內容的數據交換規範，起源於網景通訊公司（Netscape）的推技術（push technology），將訂戶訂閱的內容傳送給他們的通訊協同格式（Protocol）。RSS可以是以下三個解釋的其中一個：

* Really Simple Syndication（RSS 2.0）
* RDF （Resource Description Framework） Site Summary（RSS 0.91, RSS 1.0）
* Rich Site Summary （RSS 0.9 and 1.0）

但其實這三個解釋都是指同一種企業聯合組織（Syndication）的技術。

目前RSS規範的主要版本有0.91、1.0和2.0。

0.91版和1.0版完全不同，風格不同，制定標準的人也不同。0.91版和2.0版一脈相承。1.0版更靠攏XML標準。現時世界多數知名新聞社網站都提供RSS訂閱支持。

為什麼使用RSS？

RSS讓網站能夠製造內容摘要，並讓用戶以不同的方式瀏覽這些摘要。

如果沒有RSS，用戶可能需要每天去登陸某個網站（如雅虎）去瀏覽已更新的新聞，這可能是一件非常浪費時間的事情。目前已經有很多網站向用戶提供了免費的RSS饋送（RSS feed）。那麼，用戶就不必每天登陸到該網站檢查更新的新聞，他們只需要下載一個RSS閱讀器，然後將他感興趣的網站提供的新聞RSS饋送添加到這個閱讀器，在本地電腦上運行閱讀器就可以查看到新聞的更新內容。

[編輯] 範例

下列的例子是一個 RSS 1.0 的檔案內容。








XML.com
http://xml.com/pub

XML.com features a rich mix of information and services
for the XML community.












XML.com
http://www.xml.com
http://xml.com/universal/images/xml_tiny.gif



Processing Inclusions with XSLT
http://xml.com/pub/2000/08/09/xslt/xslt.html

Processing document inclusions with general XML tools can be
problematic. This article proposes a way of preserving inclusion
information through SAX-based processing.




Putting RDF to Work
http://xml.com/pub/2000/08/09/rdfdb/index.html

Tool and API support for the Resource Description Framework
is slowly coming of age. Edd Dumbill takes a look at RDFDB,
one of the most exciting new RDF toolkits.




Search XML.com
Search XML.com's XML collection
s
http://search.xml.com



The following is an example of an RSS 2.0 file.




Liftoff News
http://liftoff.msfc.nasa.gov/
Liftoff to Space Exploration.
en-us
Tue, 10 Jun 2003 04:00:00 GMT
Tue, 10 Jun 2003 09:41:01 GMT
http://blogs.law.harvard.edu/tech/rss
Weblog Editor 2.0
[email protected]
[email protected]


Star City
http://liftoff.msfc.nasa.gov/news/2003/news-starcity.asp
How do Americans get ready to work with Russians aboard the
International Space Station? They take a crash course in culture, language
and protocol at Russia's Star City.
Tue, 03 Jun 2003 09:39:21 GMT
http://liftoff.msfc.nasa.gov/2003/06/03.html#item573



Space Exploration
http://liftoff.msfc.nasa.gov/
Sky watchers in Europe, Asia, and parts of Alaska and Canada
will experience a partial eclipse of the Sun on Saturday, May 31st.
Fri, 30 May 2003 11:06:42 GMT
http://liftoff.msfc.nasa.gov/2003/05/30.html#item572



The Engine That Does More
http://liftoff.msfc.nasa.gov/news/2003/news-VASIMR.asp
Before man travels to Mars, NASA hopes to design new engines
that will let us fly through the Solar System more quickly. The proposed
VASIMR engine would do that.
Tue, 27 May 2003 08:37:32 GMT
http://liftoff.msfc.nasa.gov/2003/05/27.html#item571



Astronauts' Dirty Laundry
http://liftoff.msfc.nasa.gov/news/2003/news-laundry.asp
Compared to earlier spacecraft, the International Space
Station has many luxuries, but laundry facilities are not one of them.
Instead, astronauts have other options.
Tue, 20 May 2003 08:56:02 GMT
http://liftoff.msfc.nasa.gov/2003/05/20.html#item570