Scrolls like butter
The idiom “scrolls like butter” is used to describe a graphical user interface that scrolls very smoothly, especially under conditions where scrolling would be processor intensive. The phrase is attributed to Steve Jobs. During his January 2006 keynote address, Jobs was noticeably under the weather. His occasional dry cough and apparent lack of energy were consistent throughout the keynote.
During his presentation demo of iLife ’06’s iPhoto, Jobs showed off the new version’s features: the addition of photocasting, construction of cards and calendars, and the ability to scroll through thousands of thumbnailed pictures with graphical ease and grace, highlighted by Jobs stating that “this new version just scrolls like butter.”
It has been speculated that Jobs may have meant to use the classic phrase “like a hot knife through butter,” but instead misspoke, possibly due to his illness. (Source: Wikipedia)
