> In all my years of working with text editors, I don't think I've ever found myself thinking "This viewport is too small. I wish I could quickly resize it to just the width of the text, and maybe the height of the screen, or maybe something else, depending on what I'm doing." When my window is too narrow or whatever, I usually just (a) maximize it (which you can't to on osx)

I use Sublime Text 2 on OS X. When I click on the zoom button, it maximises the editor window to the entire width and height of the screen.