Longhorn将要从底层（the deep platform support for RSS）开始支持RSS。

2008server

Longhorn将要从底层（the deep platform support for RSS）开始支持RSS。

1）Browse, Search, Subscribe
We think that RSS is becoming a critical tool for businesses to communicate with customers and we want that to happen even faster.
Robert will talk about how businesses can use RSS to create strong, ongoing connections with their customers. I’ll talk about how the RSS platform in Windows Vista will make tapping into the power of RSS easier, as well as some of the new opportunities that businesses and bloggers can expect.
2）RSS Today
One estimate holds that there are over 60 million blogs worldwide as of April 2005 (including 14 million hosted by MSN Spaces), a majority of which are available via RSS (or similar formats).
MSN Spaces占了23%。
3）Platform Components（平台组件）
The RSS platform support in Longhorn has three parts:
* Common RSS Feed List gives application developers access to the list of feeds to which the user is subscribed.
* Common RSS Data Store is a common data store that provides a single location where applications can access any content that has been downloaded to the PC via RSS—including text, pictures, audio, calendar events, documents, and just about anything else. All applications will have access to this content for creating rich user experiences.
* RSS Platform Sync Engine automatically downloads data and files (enclosures) for use by any application. It is designed to be as efficient as possible when downloading this information, using idle network bandwidth whenever possible, in order to limit the impact on the user’s Internet experience. Developers can use the platform to get RSS data without having to manage details like synchronization schedules or subscriptions.
Common RSS Feed List：用来访问用户订阅的所有Feeds列表；

Common RSS Data Store： RSS数据中心。这些数据是指已经下载到本地的RSS数据信息，包括文本、图像、音频、视频、日历文件等；
RSS Platform Sync Engine：利用网络空闲时间自动下载同步Feeds的信息（包括数据和附件）。在后面可以看到，其实还包括用户手动触发的同步更新以及按照Feed提供者所推荐的同步周期来进行同步。

2008server

4）Discovery and Subscribe
现在Firefox和Opera都已经有了类似的功能，一键点击进行订阅（前提是所有提供RSS的网页都要在<Link>中加以声明：RSS AutoDiscovery）。值得一提的是，不像Firefox和Opear那样，浏览器也是一个RSS Reader。对于Longhorn中的RSS来说，Longhorn就是一个大大的RSS Reader，IE只不过是利用这些Feeds信息的一个应用程序而已。
Update：Windows RSS Publisher’s Guide
Longhorn RSS Team发布的如何在网页中公布RSS信息。
BTW：从Longhorn RSS Team提供的Video可以看到，实际的订阅过程是，当发现提供RSS的页面是后，首先点击“RSS”按钮，可以看到此Feed的一个预览，并且提供Sort By和Search此Feed的功能，最后点击Subscribe来进行订阅。
Update : IE7 Beta1中的RSS支持。
5）Enabling New Scenarios with Enclosures
利用RSS2.0规范中的Enclosure来提供附件信息。
6）Enabling New Scenarios for Lists
这个算是被诟病最多的，微软自己提出的RSS Extension - 《Simple List Extensions》。
Many collections of interesting content are actually not time-ordered; they are sorted by such properties as priority, cost, or simple ranking. In fact, one can observe these lists everywhere in one’s daily life: to-do lists, shopping lists, sales reports. On the Web, one can readily observe lists of this type: Top 10 songs from a music site, a wish list from an online retailer, or a user’s ranking of their favorite restaurants. In many cases, one can imagine wanting to subscribe to these lists and be notified when the content is updated. In fact, some of these lists are already being published as RSS.
However, in practice, RSS is not particularly well suited for describing lists of ordered content. In part this is because clients do not understand that the feed being received represents a complete, ordered list, and process it as if it were a time-ordered feed, resulting in incorrect behavior.
Longhorn includes support for the Simple List Extensions—a set of enhancements to RSS developed by Microsoft to help Web sites publish lists of content that users can subscribe to.
解决不以时间排序的List的问题。比如：ToDO List、销售排行Top10等等。Video中给出的例子是Amozon中的Book List，可以根据最多评论、价格、日期等排序。
下面这张图就描述了现有RSS使用场景（包括Blog、新闻、PodCasting等等）与Simple List Extensions这样的Feeds的应用场景的对比。

2008server

7）Architectural Overview
系统架构图：

可见，RSS Platform Sync Engine负责从各个RSS源来获取同步信息以及附件文件，保存到Common RSS Data Store，应用程序就可以通过接口来访问这些数据信息。同时，还可以通过Common RSS Feeds List接口来访问订阅的所有Feeds信息。
RSS对象模型：

8）How to Enable RSS in Your Application
两个例子：
Subscribing to photo blogs
比如说，我浏览到一个Photo Blog，这个Blog提供RSS，并且在<Link>中声明（主要是便于浏览器发现RSS），我喜欢这个Blog的照片，于是订阅之。RSS Sync Engine会添加此RSS Feed，并且随时同步保持更新（包括RSS附件中的照片文件）。
这时，第三方应用程序，比如Screen Saver就可以通过RSS Object Model来访问RSS Data Store，获取最新的照片，并加入到屏保的显示队列中。这样，当屏保显示的时候，会将你关注的Photo Blog的照片自动的带到你的眼前。
这样，一旦你订阅过的Phto Blog有更新，这些照片将会自动出现在支持Longhorn RSS Feature的应用程序中。
Update：今天发现，Tiger中已经有这样的酷程序，而Windows平台也出现了第三方开发的RSS ScreenSaver，不过当然，这还是自己来做RSS解析的。:P
Update (2005.07.22)：从WebLeOn的Blog发现，微软推出了自己的RSS ScreenSaver。不出所料，这个程序还是需要MSN Search ToolBar。这个Toolbar已经涵盖了太多的东西：Tab Browsing, Desktop Search, MSN Search, RSS ScreenSaver。显然，还是希望IE能够作为互联网的入口。
# Personalize with background photos and news and weather information from MSN&reg; or any RSS feeds from websites you choose.
# Search the Web and click news headlines directly from the Screen Saver.
# Stay connected with MSN Hotmail&reg;, MSN Messenger, and MSN Spaces. Track how many unread Hotmail messages and current Messenger conversations you have, and display blogs and photos from your friends’ MSN Spaces.
Update(2005.07.27)：今天在MSN Search的Blog上也看到了关于MSN ScreenSaver的消息，这个软件是有MS London Team完成的。
There wasn’t really a business model behind this; someone had the idea to build this because it would be “cool for users” and so we let them go and build it.
Subscribing to calendar feeds
以GnomeDex 5.0 conference schedule为例，我参加了这次会议，并且订阅了会议议程的RSS（RSS的Enclosure中包含了每个事件的iCal文件）。RSS Sync Engine于是将这个RSS Feed加入到系统的Feed列表中，并且会按时同步更新RSS信息（包括附件中的iCal文件）。
这时，Calendar Application（Microsoft Outlook？）在启动的时候就可以通过调用RSS API来获得包含有iCal文件的RSS信息源，并注册RSS更新的系统事件（这样，当这些RSS有更新的时候，就会自动通知应用程序）。
当发现订阅了包含iCal文件的RSS - “GnomeDex 5.0 conference schedule”，Calendar Application将会自动创建一个名为“GnomeDex 5.0 conference schedule”的Calendar，并将RSS中的iCal事件添加到此Calendar中来。而且当每次RSS Sync Engine发现了更新、下载iCal文件，都会通知Calendar Application，Calendar则将会把这些事件自动添加到Calendar “GnomeDex 5.0 conference schedule”中。

jqunjian

RSS是个好东东
确实得加强