The Excel File Format
Most of you will know that Excel uses a file format based on what MSFT calls OpenXML.
This enables us to write code that can easily generate/change Office files without the need for an Office installation. For instance on a server.
Whilst there is ECMA documentation on this file format, the document with detailed descriptions of the Open XML format ("part 4" in the aforementioned link) counts an astonishing 4721 pages !!
Microsoft also has a resource on the format.
This is why I decided to write up a couple of basic pages on how to do stuff with these Open XML files. We'll start relatively simple.