Having a known maximum source code line length is a very useful thing. This way, code fragments can be automatically included into other kinds of media without breaking formatting rules. Coding standards for most large, established software projects (either open-source or proprietary) explicitly mention line length.
However, what is a good line length limit? The 80-character limit is very widespread, but how does it compare to what peoples have naturally been writing? To find out, I used a little Python script (adm/line_len_hist.py) to count line lengths for various types of files in the Madagascar code base. Pictures follow below, for all source code files (including SConstruct files) and the most prevalent file types. To my surprise, the 80-character threshold is quite relevant, and it might be worth having it as an explicit coding style suggestion on the wiki, to help new contributors!