A part of the GNOME framework, but does not require GNOME. It provides interfaces similar to DOM and SAX and an XPath implementation. Released under W3C-IPR and GNU-LGPL.

A validating parser written in C and available under the GPL.

A XML parser library written in C. It is a stream-oriented parser in which an application registers handlers for things the parser might find in the XML document (like start tags). [Open source, MIT License]

An easy interface around the XML Expat parser. [Open source, LGPL]

Article on Pyxie, a "simpler" representation of XML, and its associated tools, programmed in C.

A C library based on LibXML2. News, features overview, full documentation, and download.

Minimal non-validating parser written in C. Implements subset of SAX with namespaces. Public domain.