I tried Revise and the fact that it doesn't require you to restart Julia doesn't mean that it allows you to change code on the fly. It means that you don't have to close the REPL and restart it and that you don't have to explicitly reload code. To see the effects of a change to a function invoked in a loop you have to wait for the loop to complete and return back to the REPL. This is not really SO interactive. In CL you see the effect of any change immediatly at the next iteration of the loop. What Revise does is to automatically recompile updated code by detecting changes automatically. I hope that this interpreter brings the same level of interactivity as CL. I'll try it for sure.