When I started AFT back in 1994 I had the idea to develop a product for compressible flow in pipe systems. After AFT Fathom 1.0 was released in April 1994 I began research on numerical methods for compressible flow in pipe networks. Books and papers that claimed to offer methods for compressible flow inevitably focused on single pipe applications with adiabatic or isothermal flow - and often with ideal gases. I wanted to develop a real gas software that could model heat transfer and simulate pipe networks.