This database handles all donations and correspondence to and from donors. Letters are merged into Microsoft Word.
All the Microsoft Office products use a form of Visual Basic called Visual Basic for Applications (VBA) as their programming language.
So once you've learnt how the application works, it is no more difficult to program Word than it is Access or any of the other Office products.
Most business applications employ a database of some sort so it makes sense to write the application using Microsoft Access. However, it is common to use combine this with some programming in Word or Excel if a mail merge or export facility is required.
We've written many applications that use a combination of office products to achieve the required functionality. A common example nowadays is the automatic creation of emails.