Microsoft Excel
The types of applications you can do with Excel VBA include:
Extracting data from text files and databases into Excel.
Exporting data from Excel into text files.
Exporting data from Excel into databases.
Consolidating data from many workbooks into one.
There are an enormous range of Excel books.
John Walkenbach has written some good books on Excel VBA so it's is good for developers and have noticed some that are for business users...