Parsing EDIFACT is easy. You can find many libraries to do it. For example,
http://code.google.com/p/edicoder/
All these libraries simply break up the messages into segments.
The hard part with EDIFACT is to transform the message into some meaningful objects. This is very application specific and I doubt you will find any libraries. Even if you find one, it will be specific to a narrow field, like hotel reservation.