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.
At the heart of every business phone system is the PBX (Private Branch Exchange), which makes connections among the internal telephones of a business or other private organization and connect them to the public switched telephone network (PSTN).