Tabs are the clear winner here, since they unambiguously denote which level of indent is in use, take only one character (octet) per indent level, and can be vi

Tabs are the clear winner here, since they unambiguously denote which level of indent is in use, take only one character (octet) per indent level, and can be visually adjusted on any moderately advanced editing program to an end users taste WITHOUT modifying the source code. This __wouldn't matter__ if we all just used TABS for indent level and if spaces were ignored for that: I also prefer tabs to show in a GUI code editor at ~4 characters, but be equivalent to 8 display characters in terminal modes (I guess EM size, but when I care about those I really want a 'fixed width' font, so toss all of the complexity aside please).