Comment 135 for bug 32561

We'd be lucky if Pango's implementation of letter-spacing matches CSS's in terms of exactly where spacing is allowed and where it's placed (not really dictated in CSS yet, but will be). Ditto for word spacing, justification spacing, tab expansion. There's also non-text elements in lines, relative positioning, CSS borders, hyphenation ... Even if we have lots of luck, we can't expect Pango and CSS to always match for all time, and designing for that would be foolish. Even more so when you bring other platforms into the equation.