...which makes you feel the system is "alive", hence one **huge benefit** of Smalltalk: its debugger which enables on the fly debbuging... and also test driven development (real one [1]) where you can run incomplete code and code what's missing iteratively when you need it (Smalltalk is a live system, not only a language as somebody said lately).

C�drick

[1] see in particular this webcast: http://www.pharocasts.com/2010/01/starting-with-sunit-and-debugger.html