Nexus 1 is a data format containing character state data. The BiotaPhy project often uses Nexus to store trees with annotations for the nodes in those trees.
#NEXUS BEGIN TAXA; DIMENSIONS NTAX=3; TAXLABELS A B C ; END; BEGIN TREES; TREE 1 = (A,(B,C)); END;
Footnotes
http://wiki.christophchamp.com/index.php?title=NEXUS_file_format
NeXML
Phylip