Much of this seems to have more to do with the way Lisp environments work than with the language itself.<p>Couldn't the same sort of thing be done with any language that can be interpreted or incrementally compiled or is there something fundamentally different about Lisp that makes this possible ?<p>For example could Python be used this way ? I usually use a traditional edit/run development cycle with Python programs but I'd be curious if anyone finds other development modes more productive.