XML formats

A list of a site's URLs with optional freshness hints, read by every major search engine. One <urlset> root, one <url> per page, <loc> mandatory.

.xml · .xml.gz

A sitemap of sitemaps, used once a site outgrows a single 50,000-URL file. Indexes cannot nest: every child must be a sitemap, not another index.

.xml · .xml.gz

The most widely deployed syndication format: namespace-free at its core, extension-heavy in practice, and unopinionated about almost everything.

.xml · .rss

The IETF-standardised syndication format: namespaced from the root, strictly typed, and unambiguous about dates in a way RSS 2.0 never was.

.xml · .atom

The message envelope for SOAP web services — still the backbone of banking, logistics and telecom, with its version carried by the namespace URI.

.xml

The dominant XML schema language: namespace-aware, richly typed, and itself written in XML — so schemas diff and version-track like the payloads they govern.

.xsd

The machine-readable contract for a SOAP service: operations, messages, bindings and endpoints, with an inline XSD describing its own types.

.wsdl · .xml

A transformation program written in XML, used to reshape one XML vocabulary into another — common wherever a partner payload meets an internal format.

.xsl · .xslt

A vector image format that is genuine XML, and therefore both diffable and a security surface: scripts and external references travel inside the file.

.svg · .svgz

A nested outline format whose meaning lives entirely in attributes, used almost universally for exporting and importing feed subscriptions.

.opml · .xml

A graph serialisation in XML, where identity lives in rdf:about and nesting means relationship. Also the real format behind documents labelled RSS 1.0.

.rdf · .xml

The interchange format for GPS waypoints, routes and recorded tracks — three shapes that look alike, and that devices disagree about which to emit.

.gpx

An OGC standard for geographic annotation: placemarks, geometry and the styles that render them, originating in Google Earth and still shaped by it.

.kml · .kmz

The localisation interchange format that carries source text, its translation and how far that translation has got, one <trans-unit> per string.

.xlf · .xliff

The OASIS invoice document behind Peppol and most European e-invoicing mandates, splitting its vocabulary across three namespaces you must all declare.

.xml