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.
The plumbing fixture that an outdoor water hose is attached to is usually called a hose bibb, spigot or faucet. It may also be called a coupling, a connector or an adapter.