XSLT
XSLT (Extensible Stylesheet Language Transformations) is a declarative programming language used for transforming XML documents into other formats, such as HTML, plain text, or other XML structures. It is part of the XSL (Extensible Stylesheet Language) family and operates by applying templates defined in an XSLT stylesheet to the nodes of an XML source document. This enables data conversion, presentation, and restructuring tasks in a standardized way.
Developers should learn XSLT when working with XML-based data processing, such as in web services, document management systems, or publishing workflows, where transforming XML to different formats is required. It is particularly useful for generating dynamic web content from XML data, converting between XML schemas, or creating reports and documents, as it provides a powerful, template-driven approach that integrates well with XML technologies like XPath and XSL-FO.