The initial release of the CIFTI-2 XML parsing/manipulating/writing code is available on the NITRC download page, http://www.nitrc.org/frs/?group_id=454.  It additionally supports CIFTI-1 XML, but note that supporting CIFTI-1 requires dealing with reversed dimensions in the NIfTI-2 header (CIFTI-2 does not have this problem).  It also does not include code for reading or writing NIfTI-2 files.

This code is released under the BSD 2-clause license.