Carsten, Thibault and others-

As discussed in yesterday's developer meeting, the core documentation for EM is now complete here:  http://docs.limesurvey.org/Expression+Manager+for+Developers
You should also read http://docs.limesurvey.org/Expression+Manager for additional details and nuances.

Please let me know if there are other categories of information you'd like me to add.

/Tom