This is GNU Bash, version 3.0.  Bash is the GNU Project's Bourne
Again SHell, a complete implementation of the POSIX.2 shell spec,
but also with interactive command line editing, job control on
architectures that support it, csh-like features such as history
substitution and brace expansion, and a slew of other features. 

WWW: http://cnswww.cns.cwru.edu/~chet/bash/bashtop.html