libxslt is an open-source software library designed for transforming XML documents into various formats using the XSLT (Extensible Stylesheet Language Transformations) standard. It allows developers to apply stylesheets to XML data, enabling the conversion of XML into HTML, text, or other XML formats. The library is written in the C programming language and is part of the GNOME project. It is known for its speed and efficiency, making it a popular choice for applications that require XML processing. libxslt is often used in conjunction with libxml2, a library for parsing XML documents.