Roller is a nice little utility that lets us generate numbers from dice expressions popular in pen and paper role playing games. Haskell implementation of dice notation.
$ roller "4"
4$ roller "4d5"
10$ roller "3d10 + 2"
23$ roller -v "3d10 - 2"
16 [7,3,8,-2]$ roller -n5 "1d4"
1
3
3
2
3