XJDF stands for "Exchange Job Definition Format". XJDF is an extensible, XML-based data interchange format built upon more than 15 years of experience with JDF.
The major conceptual change is that XJDF no longer attempts to model the entire job as one large “job ticket” but rather specifies an interchange format between two applications that are assumed to have an internal data model that is not necessarily based on XJDF. Thus, each XJDF ticket specifies a single transaction between two parties. (Text)