Quicksort was invented by
C.A.R. Hoare. The important part is the efficient
in-place partition algorithm.
In addition to the disadvantages ariels discusses, quicksort also has the problem of not being stable---that is, it does not preserve the order of elements with the same sort key. Additionally, it, unlike merge sort, requires random destructive access to the sequence being sorted---making it ill-suited to sorting lists, or to use in pure functional languages.