This is the AMbicious STanDard library, available under GPL2.

It is a collection of miscellaneous Ruby modules by Minero Aoki.
Several modules of his are using those modules.

aliasing.rb: alias for class method and module function
bench.rb: very simple benchmark
bug.rb: 'bug!' method
const.rb: const method
d.rb: p object
must.rb: must/must_have/must_be methods
protect.rb: protect from exceptions
timer.rb: timer class
version.rb: VersionNumber class