And/or get rid of the insanely narrow fixed-width centered column and let the user resize it along with the window. So many programming blogs put code samples in a fixed-width unresizable column.

Not sure about this suggestion. Long lines of text are difficult for eyes to track. That's why you'll see tools like "Clearly" format text into narrower columns. Apparently there is an optimum number of words per line.

Here is one write up on it: http://baymard.com/blog/line-length-readability

Short lines are definitely good for prose (books makers have known this centuries), but I find that code is different. I tend to find code that has longer lines is much easier to read than code that rigidly adheres to (say) an 80 column length limit.

I think it's because I tend not to read code in order. I like to see the shape of it, look at just the beginning of the line to see what might be going on in that line and only looking at the whole line if it seems relevant to what I'm doing. Normally just seeing the first 20 or so characters (or pulling some keywords out from syntax highlighting) is enough to understand the broad strokes.

Doesn't help me when I'm reading on an iPad or on the train on an iPhone. Just sayin'.

Good point and I've removed the user/host part, but the session part is relevant. With Compose's Write Stuff programme (compose.io/write-stuff) we try to retain the contributing authors content and styling as far as possible.