Take a look at Pharo. I did and Pharo is now my primary personal development tool. Another thing that convinced me were videos by Laurent Laffont. Laffont uses

Take a look at Pharo. I did and Pharo is now my primary personal development tool. Another thing that convinced me were videos by Laurent Laffont. Laffont uses Pharo, IMHO, the way it is supposed to be used - he uses the debugger intensively during development to prompt him to for the next step. His development workflow is guided by a general outline in his mind, and the details are filled in by the debugger prompts. His videos can be found at Pharocasts.