[JSR_FDED]

I’ve used it when I didn’t want the hassle of another dependency

[jhallenworld]

I've used it on a tiny microcontroller because libc's quicksort was huge.

[bxparks]

Shell sort is sooo much faster than Bubble sort for tiny microcontrollers, for only a little bit more flash memory, like 40-100 bytes. If that's too much, then Insertion sort is 6X faster than Bubble sort, for only 10-20 bytes of extra flash.