Just wanted to pass on a cosmetic thing I found. On OS X, when the mouse if over text, and I press CTRL, CMD + D (to show the OS X dictionary) it shows up as shown in the attached screenshot.
(the word is achievable, which is in the sublime text editor. the os x (I assume it's OS X doing it) yellow highlight shows the word, but for some reason it is smaller than the word underneath, and it shows through on the right).
Tiny, tiny thing I know. But thought I'd pass on nonetheless.