The Nessus Security Scanner is not only another security auditing tool. The Nessus Security Scanner is free, open-sourced and wants to be easy to use. Nobody funds the Nessus project. The authors give their free time to write their part. Jordan Hrycaj gives his free time to write the cipher layer.
Users give their free time to report bugs or suggest enhancements.
No special reason. I needed a name when I started it. Mainly because the names my project and security scanner were too vague and too common. All the compilation options are passed to the configure script of the nessus-libraries package. The only working compilation option at this time is the cipher layer.