SCEW - Simple C Expat Wrapper
- An easy interface around the XML Expat parser. [Open source, LGPL]
- http://www.nongnu.org/scew/

The Expat XML Parser
- 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]
- http://expat.sourceforge.net/

XMLproc
- Minimal non-validating parser written in C. Implements subset of SAX with namespaces. Public domain.
- http://www.saunalahti.fi/~samiuus/toni/xmlproc

RXP
- A validating parser written in C and available under the GPL.
- http://www.cogsci.ed.ac.uk/~richard/rxp.html

Pyxie [XML.com]
- Article on Pyxie, a "simpler" representation of XML, and its associated tools, programmed in C.
- http://www.xml.com/pub/a/2000/03/15/feature/index.html

libxml - The XML library for Gnome
- 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.
- http://www.xmlsoft.org

Expat
- A non-validating XML 1.0 parser written in C.
- http://www.jclark.com/xml/expat.html