LGML
Linguistics Markup Language (LGML) is an XML-based framework for describing the syntax and semantics of natural languages.
Features
LGML uses many tag sets to annotate one piece of text for compatibility with different applications.
Annotating semantic information about words. For example, using WordNet synset number to identify the meaning of a word. Again, this is flexible to allow any type of semantic annotation.
Having it XML-based allows it to be embedded with different types of XML-based documents, such as e-books, for easy information retrieval.