Web Slice

Web Slices are a web feed technology based on the hAtom Microformat that allows users to subscribe to portions of a web page. Microsoft developed the Web Slice format, and published a specification under their Open Specification Promise. The specification is not published by any independent standards body. Introduced in Internet Explorer 8 Beta 1, Web Slices can be previewed in a fly-out window. Internet Explorer 8 and 9 were the only browsers to support Web Slices natively, although Mozilla Firefox had support via an add-on called webchunks.

Implementation
A Web Slice has 9 properties: the Web Slice id, entry title, entry content, end time, alternative display source, alternative navigation, alternative update source, and time to live. The 3 required properties are: the Web Slice id, entry title, and entry content.

To disable Web Slices on a web page, add:

To specify the default web slice on a page with multiple web slices, add:

Mozilla Firefox
While Firefox does not have built in support for web slices, extensions have been created to give the ability to read web slices.

WebChunks
WebChunks is a Mozilla Firefox 3 implementation of Microsoft Webslices. It allows you to "follow" an area of a web page through a dedicated feed bookmarked in a new toolbar. With Greasemonkey, WebChunks can insert webchunks or webslices markup into any web page so the Webchunks extension handles it.

Fireclip
Fireclip is a Firefox addon that lets you "clip out" parts of a website and watch them for changes. It lets you track specific parts of a website in a similar manner to web slices.

PageSlices
Pageslices was another Firefox addon that allowed not only storing parts of websites but also organizing them by adding on custom pages.

Google Chrome
Google Chrome, like Firefox, does not have built in support for web slices. However, the extension API new to Chrome 4 allows extensions to be created to give the ability to relatively simply create arbitrary webslices of any content from any page.

Opera
Although it was rumored that Opera 10 would have support for web slices, this did not come to pass. Opera does have a "widgetize" feature likened to web slices which allows web pages to be displayed on a user's desktop.

Development

 * Web Slice Format Specification - Version 0.9, MSDN
 * Create a dynamic Web Slice in 5 minutes, IE8 Blog
 * Internet Explorer 8 Web Slice Style Guide, MSDN
 * Web Slices, Internet Explorer 8 Readiness Toolkit
 * WebSlices, Internet Explorer 8 Beta 1 Whitepapers
 * Internet Explorer 8 for Developers: Web Slices, MSDEV.com