In one of my projects, we need to send emails to our suppliers with new orders as Excel spreadsheets. We used to do it by hand, but when you have 10 suppliers and you make 200 products orders per week, after some time you are just tired of creating Excel spreadsheets, mailing them and so on. So, my task was to implement automatic spreadsheets creation with PHP.
His example creates a basic file with a set of "Items", some formatting and a set of code/title items to fill out each row. The end result can then be packaged up and sent out as a complete Excel XLS file.