About Problems of PDF

For distributing electronic documents the document for-mat is a key factor. The Portable Document Format (PDF) is very popular for text-based documents. Cur-rently also 3D-documents are distributed using that for-mat. PDF is also very often used as primary document format for lecture notes. Unfortunately there are some problems related to the format especially when inter-activity is an issue in such teaching and learning envi-ronments. On the one hand it is necessary to person-alize content for each user, therefore documents must be adapted to user’s preferences. On the other hand users have to interact with others via documents, i.e. they want to make some comments for other users on the topic. In PDF comments (aka annotations) are sup-ported. However, one needs to install special tools for using that feature of the document format. To over-come this problem documents must be enhanced on the server-side before being transfered to users. In this arti-cle we report about such an enhancement