Respectfully, is it possible you've confused Q with something else? I compressed and minified both caolan/async and kriskowal/q. Result: async is 3.4 KB, q is 4

Respectfully, is it possible you've confused Q with something else? I compressed and minified both caolan/async and kriskowal/q. Result: async is 3.4 KB, q is 4.1 KB. I grant you that mbostock's queue is even smaller, but all are so tiny as to be a trivial download even on mobile. The important issue here is IMHO not the size of the libraries, but how much they help you write maintainable code.