Libroxml is a small and powerful xml library originaly designed for embedded systems.
Its small size, great performances, and numerous functionnalities provided with a very simple API makes it a good solution for even non embedded developments.
checkout http://www.libroxml.net for more information and online documentation.
libroxml inclusion in debian is pending (see RFP #574668 ). In the mean time, you can use my personnal repository by copying the following line in your source.list.
deb http://debian.libroxml.net/mirror/ debian contrib