The answer is (also confirmed by other replies) Windows. It seems in the Unix world, everyone uses UTF-8 (without BOM of course) and text encoding mistakes don'

The answer is (also confirmed by other replies) Windows. It seems in the Unix world, everyone uses UTF-8 (without BOM of course) and text encoding mistakes don't exist. When you involve Windows, which likes a random mix of UTF-16, UCS-2, CP1252, and I guess also UTF-8 with BOM, you're screwed.