An xkcd downloader in pure Node.js, no packages involved.
$ npm install -g nkcd$ nkcd [comic number] [download directory]
# Download latest comic in the current directory
$ nkcd
# Download latest comic to the "comics" directory
$ nkcd comics/
# Download comic number 614 to the current directory
$ nkcd 614
# Download comic number 614 to the "comics" directory
$ nkcd 614 comics/