One of the tools I created recently output its data in CSV format. The Python CSV library is quite nice. However, opening the file in Excel gave the error “SYLK: file format is not valid” or “Excel has detected that ‘test.csv’ is a SYLK file, but cannot load it.” OpenOffice handled the file just fine.
It turns out that a CSV file with the first two bytes set to “ID” (case-sensitive) is detected as a different file format by Excel. And this is why I hate software.