I recently noticed that the Menlo font is rendered differently in OS X El Capitan, depending on the application being used. After tinkering a bit with AppleFontSmoothing, I noticed that the crucial difference was by how Terminal rendered white/bright text on black/dark background compared to other applications like Emacs, Xcode and TextEdit. While the other applications render fonts "heavier" in this configuration compared to black text on white background, I couldn't see any difference in Terminal. The effect is - in my opinion - a leaner and more readable text. Please see attached screenshot for comparison.
Xcode and TextEdit will render the font similarly to Emacs when AppleFontSmoothing is globally set to minimal. What's going on here, is there a way to apply this in other applications as well? I think the way Terminal renders the font is a major improvement, and would like to see this in all applications.