zsh

The Z shell is a feature-rich UNIX-like shell. It is usually seen as a continuation of the original sh, while improving on many features on other shells.

Those include advanced ksh-style globbing, cyclic completion, and lots more. It is released under a BSD-style license.

(switch from bash, you will not regret it. It is also useful to have oh my zsh.)

Something you're likely to hear from a thug on the street.