Axiom is  a general purpose Computer Algebra system. It is useful for research and development of mathematical algorithms. It defines a strongly typed, mathematically correct type hierarchy. It has a programming language and a built-in compiler.
Polybutylene is simply a type of plumbing material that was manufactured between the late 70's and early 90's. It is thought that it was installed in over 6 million homes during that time period.
Definition: BRB is a Web abbreviation commonly used in blogs, microblogging applications, forums, and Web sites. BRB is an acronym for Be Right Back. Also Known As: B4N (Bye for Now), BBL (Be Back Later). Examples: Hey, somebody's knocking at the door-BRB!