The Model Language (TML) is a simple langauge for describing usage models. It supports composition, constraints, and automated testing information. It is the most common means to create and edit usage models.
Model Markup Language (MML) is an XML extension for describing usage models. It supports the same information as TML. Documentation of MML can be found in the JUMBL user's guide, as well as online.
Extended Model Markup Language (EMML) is an XML extension for describing usage models directly in terms of usage variables. For certain applications, this approach is more natural. Complete documentation on EMML can be found in the JUMBL user's guide.