LIBXML

libxml, commonly known as libxml2, is a free, open-source software library written in C that provides facilities for parsing, manipulating, and validating XML documents. Developed as a core component of the GNOME project, it is widely used by software across platforms to process XML data.

Libxml2 exposes multiple APIs to support different programming styles. The DOM API lets you build and modify the in-memory document tree; SAX2 offers event-driven parsing; a pull parser enables incremental processing. It also provides XPath evaluation, XInclude support, and validation via XML Schema and RELAX NG. HTML parsing is supported, and the library can read XML from files, memory buffers, or URLs.

In addition to parsing, libxml2 offers serialization, namespace handling, entity management, and a rich set of utilities for navigating and transforming XML documents. It serves as a foundational library for many toolchains and is used by bindings in Python, Ruby, Perl, PHP, Java, and more; libraries such as lxml and libxslt rely on it.

Licensing is permissive, with an MIT/X11-style license that permits broad reuse in both open-source and proprietary software. The project is cross-platform, running on Unix-like systems as well as Windows and macOS, and is maintained by an active open-source community.

Security considerations include the general risks of XML processing, such as external entity processing. Developers can mitigate these by configuring the parser to limit or disable such features and by keeping the library up to date.