100 characters seems a pretty reasonable compromise. Keeps lines from getting too long and hard to follow, but you're not splitting lines all the time just to k

100 characters seems a pretty reasonable compromise. Keeps lines from getting too long and hard to follow, but you're not splitting lines all the time just to keep under the limit, which also reduces readability. If you're having trouble fitting two 100 character wide files side by side, there's two things you need to do: #1 - get a screen with a decent resolution. 1920px wide should be standard for any developer worth his salt. Yes, this means "don't develop on a 13 inch laptop screen"... you're a developer, this is the main tool to do your job, make it a decent one. #2 - use a real font. Courier New (or whatever the corollary is on Linux/OSX) is not a real font. I prefer proggy fonts (http://www.proggyfonts.com/index.php?menu=download http://www.proggyfonts.com/index.php?menu=download)... they are incredibly more compact and still very readable... you get significantly more characters on the same line.