Emacs

Blatant advertising for one of my packages: Embark has convenient key bindings for all of the commands discussed in this article. If point is on active region and you call embark-act, the s prefix has all of the sort commands there, reverse-region is on r, and delete-duplicate-lines is on d. I tend to forget all the sort commands, so I often call embark-act on a region, press s, and then C-h to get a list of them.