FeedSync for Atom and RSS, previously Simple Sharing Extensions, are extensions to

RSS RSS ( RDF Site Summary or Really Simple Syndication) is a web feed that allows users and applications to access updates to websites in a standardized, computer-readable format. Subscribing to RSS feeds can allow a user to keep track of many ...

and

Atom Atoms are the basic particles of the chemical elements. An atom consists of a atomic nucleus, nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished fr ...

feed formats designed to enable the bi-directional synchronization of information by using a variety of data sources. Initially developed by

Ray Ozzie Raymond "Ray" Ozzie (born November 20, 1955) is an American software industry entrepreneur who held the positions of Chief Technical Officer and Chief Software Architect at Microsoft between 2005 and 2010. Before Microsoft, he was best known for ...

, Chief Software Architect at

Microsoft Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The ear ...

, it is now maintained by Jack Ozzie, George Moromisato, Matt Augustine, Paresh Suthar and Steven Lees.

Dave Winer Dave Winer (born May 2, 1955, in Queens, New York City) is an American software developer, entrepreneur, and writer who resides in New York City. Winer is noted for his contributions to outliners, scripting, content management, and web service ...

, the designer of the

UserLand Software UserLand Software is a US-based software company, founded in 1988, that sells web content management, as well as blogging software packages and services. Company history Dave Winer founded the company in 1988 after leaving Symantec in the spr ...

RSS specification variants, has given input for the specifications. The last version of FeedSync for Atom and RSS specification is 1.02. FeedSync for Atom and RSS is licensed under the

Creative Commons Creative Commons (CC) is an American non-profit organization and international network devoted to educational access and expanding the range of creative works available for others to build upon legally and to share. The organization has release ...

Attribution-ShareAlike License (version 2.5) and the

Microsoft Open Specification Promise The Microsoft Open Specification Promise (or OSP) is a promise by Microsoft, published in September 2006, to not assert its patents, in certain conditions, against implementations of a certain list of specifications. The OSP is not a licence, but ...

. The scope of FeedSync for Atom and RSS is to define the minimum extensions necessary to enable loosely cooperating applications to use Atom and RSS feeds as the basis for item sharing – that is, the bi-directional, asynchronous synchronization of new and changed items amongst two or more cross-subscribed feeds. Note that while much of FeedSync is currently defined in terms of Atom and RSS feeds, at its core what FeedSync strictly requires is: * A flat collection of items to be synchronized * A set of per-item sync metadata that is maintained at all endpoints * A set of algorithms followed by all endpoints to create, update, merge, and conflict resolve all items This means that FeedSync can be implemented by almost any programming language have its metadata represented in many structured data formats.

Examples

RSS feed

To Do List A list of items to do https://www.example.com/something/foo/bar/
type="complete" />
type="aggregated" title="To Do List (Jacks Copy)" /> Buy groceries Get milk, eggs, butter and bread

Atom feed

To Do List A list of items to do Ray Ozzie 2005-05-21T11:43:33Z urn:uuid:60a76c80-d399-11d9-b93C-0003939e0aaa
type="complete" />
type="aggregated" title="To Do List (Jacks Copy)" /> Buy groceries Get milk, eggs, butter and bread urn:uuid:60a76c80-d399-11d9-b93C-0003939e0aa0 Ray Ozzie 2005-05-21T11:43:33Z

POX item

Buy groceries Get milk and eggs

JSON item

Examples of real world use

There are several examples of "real world" use of FeedSync feeds to synchronize data between applications.

FeedSync service

This prototype developer service is an implementation of HTTP-based FeedSync endpoint. Applications can use HTTP GET and POST commands to synchronize feeds, where the latter performs the FeedSync merge operation on the feed hosted by the FeedSync Service. The service is not active anymore.

Strong Angel III

FeedSync feeds were used extensively at the Strong Angel III exercise in August 2006 as a lightweight middle-ware to link applications from

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ESRI Environmental Systems Research Institute, Inc., doing business as Esri (), is an American Multinational corporation, multinational geographic information system (GIS) software company headquartered in Redlands, California. It is best known for ...

and others on desktops and mobile devices. The service is not active anymore.

ROME project

The comprehensive Java RSS project
ROME
is an implementation of the FeedSync specification since it creates a

Java Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...

layer for developers to create apps that will use the FeedSync service.

Mesh4x

Mesh4x
an open-source set of libraries, tools, applications and services for mesh-based applications, uses FeedSync as the versioning standard, and implements a Feedsync-inspired packet-based protocol to synchronize data over SMS text messages.

References

External links

Specifications

* *
RSS 2.0 Specification by Dave Winer

Atom Specification

Code

*
FeedSync Service Samples

SSE for .NET Codeplex project

Articles

Deprecated blog entry by Ray Ozzie on Really Simple Sharing

{{Web syndication RSS Web syndication formats XML-based standards