Atom Landscape Overview v2

Atom and the Atom Publishing Protocol (AtomPub) will become one of the most important content types on the web, and this trend has only started. AtomPub turns Atom into a read/write technology, which makes it much more powerful and widely applicable. it also adds features such as service discovery and category descriptions to Atom. the core documents have been published as RFCs:

• RFC 4287: The Atom Syndication Format is an XML-based Web content and metadata syndication format.
• RFC 5023: The Atom Publishing Protocol (AtomPub) is an application-level protocol for publishing and editing Web resources. The protocol is based on HTTP transfer of Atom-formatted representations.

three other RFCs define rather small but very useful extensions to the basic Atom format, which are likely to be useful in many scenarios:

• RFC 4685: Atom Threading Extensions presents a mechanism that allows feeds publishers to express threaded discussions within the Atom Syndication Format.
• RFC 4946: Atom License Extension defines an extension to the Atom Syndication Format for describing licenses associated with Atom feeds and entries.
• RFC 5005: Feed Paging and Archiving defines three types of syndicated Web feeds that enable publication of entries across one or more feed documents. This includes paged feeds for piecemeal access, archived feeds that allow reconstruction of the feed's contents, and feeds that are explicitly complete.

more useful extensions are currently under development, here are the active ones:

• draft-saintandre-atompub-notify: Transporting Atom Notifications over the Extensible Messaging and Presence Protocol (XMPP) describes a method for notifying interested parties about changes in syndicated information encapsulated in the Atom feed format, where such notifications are delivered via an extension to the Extensible Messaging and Presence Protocol (XMPP) for publish-subscribe functionality.
• draft-snell-atompub-bidi: Atom Bidirectional Attribute adds a new attribute to the Atom Syndication Format used to indicate the base directionality of directionally-neutral characters.
• draft-snell-atompub-feature: Atom Publishing Protocol Feature Discovery introduces extensions to the Atom Publishing Protocol Service Document format for expressing metadata about the behaviors, functions and capabilities supported by an Atom Publishing Protocol collection.
• draft-snell-atompub-tombstones: Atom Syndication Format Tombstones defines mechanisms by which Atom Feed publishers can explicitly indicate that specific Atom Entries have been removed from an Atom feed.

this last one seems to be abandoned (at least the I-D document is expired, but this does not necessarily mean that it will not be re-published at some point in time):

• draft-snell-atompub-feed-index: Atom Ranking Extensions defines an Atom Syndication Format extension for numerically ranking entries within a syndication feed.

my goal is to keep this collection of Atom-related specifications and standardization activities up-to-date and re-publish it occasionally, so if any of the information looks outdated, or something is missing, please let me know! thanks!

[[ January 22, 2008: there now is a static page for the Atom Landscape Overview, please visit that page for the latest version. ]]