The Single Document Interface

AbiWord is a Single Document Interface (SDI). That is, one AbiWord window can contain only one document at once. If you open another document or create a new one, a new AbiWord window will appear. Conversely, closing the AbiWord document will close the document.

This is the opposite of Multiple Document Interface (MDI) programs, such as Microsoft Word 97, where all the documents are contained in the one and only Word window. Closing a document will not result in closing Microsoft Word.

The SDI technology was adopted for AbiWord for two major reasons:

1. Since AbiWord is being developed for several platforms at once (Windows, Unix and soon Mac), it was decided to stress the uniformity of these versions. Since Unix is based on the single document interface (SDI), that is what we decided to use. Thus every open document in AbiWord has a button on the taskbar.
   
   
2. The most familiar application to users today is without doubt the Internet browser. Most popular browsers today use the SDI concept. From this, most users are now used to this concept and less and less used to the alternative, the multiple document interface. This reinforces the choice of this technology. Thus, new users do not have to worry about knowing how AbiWord works; it works just the way they expect. So new AbiWord users are not disoriented.