Program testing can be a very effective way to show the presence of bugs, but is hopelessly inadequate for showing their absence.
Edsger Wybe Dijkstra
Dutch computer scientist. One of the most influential members of computing science’s founding generation. Helped shape the field of computer science through his fundamental contributions to: algorithm design, programming languages, program design, operating systems, distributed processing, formal specification and verification and design of mathematical arguments. Received the 1972 Turing Award and was the Schlumberger Centennial Chair of Computer Sciences at The University of Texas from 1984 until 2000.