CWXML is an high-performance, open-source C-language library for parsing and generating XML and BXML (Binary eXtensible Markup Language) formats with a straightforward API. Initial testing indicates that CWXML is 3 or more times faster at parsing XML (text data) than other popular libraries such as expat and libxml2 (10x Xerces) and 5 to 60 times faster again at parsing BXML data. The library is being developed by CubeWerx as the reference implementation for the BXML proposed specification. The parser accepts and automatically recognizes the following formats: XML, GZIPped XML, BXML, BXML with internal GZIP, and BXML with external GZIP. It is licensed under the GNU LGPL.