MMAX: Multi-Modal Annotation in XML
Read more about this tool at:
http://www.eml-research.de/english/research/nlp/download/mmax.php
Here is a paper regarding its application in multi-layer annotations (prosodic, syntactic and discourse level):
Baumann, Stephan et al. (2004): Multi-dimensional annotation of linguistic corpora for investigating information structure. http://www.corpus4u.org/upload/forum/2006031210384389.pdf
Read more about this tool at:
http://www.eml-research.de/english/research/nlp/download/mmax.php
Here is a paper regarding its application in multi-layer annotations (prosodic, syntactic and discourse level):
Baumann, Stephan et al. (2004): Multi-dimensional annotation of linguistic corpora for investigating information structure. http://www.corpus4u.org/upload/forum/2006031210384389.pdf