What it is
XML, Extensible Markup Language, is a text format for structured data, published as a W3C Recommendation in 1998. Like HTML it uses tags, but the tags are defined by the author, so it can describe almost any kind of document or record. It was the main way systems exchanged data on the web for much of the 2000s.
XML comes with schemas for validation, namespaces, and tools such as XPath and XSLT for querying and transforming documents. JSON has replaced it for most web APIs, but XML remains common in office file formats, RSS feeds, SVG images, sitemaps and many enterprise and government integrations that are not going away soon.
How I use it
- Listed in the Marsh Canada stack, alongside PHP, MySQL, ActionScript and HTML.
- Used with ActionScript, PHP and MySQL in the interactive web work of the 2000s.
- Read when integrating with older systems and outside services that still exchange XML.
XML is the right format when a partner system requires it, or when a document needs strict validation against a schema. I keep it in the toolkit because older systems and many outside services still speak it, and being able to read both sides is part of integration work.
Questions
Can you integrate with a system that only speaks XML?
Yes. I have worked with XML since the 2000s and can translate between it and the JSON most modern systems use.
Is XML still used?
Yes, in office documents, feeds, sitemaps and many enterprise integrations, even though JSON has taken over most web APIs.