prop·er - of the required type; suitable or appropriate. "an artist needs the proper tools". dev tools aren't any different.
scrolling resizing staggering debouncing throttling slacking routing matching searching loading querying controlling parsing logging tweening easing…
Along with all the useful things for developing client-side web applications are some self-interested concepts, mostly 2D gaming related. Stuff like konami-code—Listen and handle the input: up, up, down, down, left, right, left, right, b, a. Game on! Or Blit, a simple gamecycle engine ( 60fps ). Also Hobo.js, a die-hard minimalist jQuery alternative in just 7–11k minified. There’s a lot going on in ProperJS and its all lightweight.