It is a well known fact that DITA is a great information architecture that enables single source publishing of content into different formats. “Write once and use everywhere” is a motto of it. But when it comes to DITA definition itself and DITA specializations, we have to make decisions about format we want to maintain our models in. We need to choose between DTD or XML Schema. Once this decision is made and the model is developed, it is quite a time consuming operation to change chosen format and in most cases, people would stay with originally selected format because of the effort and time involved.
DITA itself has to be supported in both formats in parallel.
But why not consider single-sourcing of DITA models? I think this would be logical step following the single-sourcing philosophy of DITA.
