"Compile time checking can't catch most non-trivial bugs. Even if you swear by it, given the advances in Java IDEs, I would have to be quite lazy (or careless)

"Compile time checking can't catch most non-trivial bugs. Even if you swear by it, given the advances in Java IDEs, I would have to be quite lazy (or careless) to write Java code that doesn't compile." You should not underestimate the power of leveraging the type system to prevent programmer error. Do not think of the type system as a nanny. Instead, think of it as an integral language tool designed for your use. Use this tool -- the type system -- to convince the compiler enforce code correctness. Using the type system in this way will allow you to spend less time writing tests, as compilation can validate correctness. If this seems unlikely, spend time with a language with a powerful type system -- such as OCaml, Haskell, Scala or F#. You will find that it is possible to implement equally succinct and considerably more correct code through leveraging language features -- including the type system. Additionally, this exercise is fundamentally applicable with the real world. Should you use F# or Scala, you will find a vast trove of existing libraries, and high-quality, high-performance VM implementations at your fingertips. Your correct code, written faster, will run faster.