You are thinking in files, no wonder.<p>Put such a Lisp image that includes all the tools and classes on an embedded device. Then connect of the network and develop/debug the functionality incrementally while it runs.<p>In Java, oh wait, I forgot class XYZ, lets push it onto the device and see if it loads. Maybe not, it needs some more class files, ... then the Java capabilities for runtime changes are kind of limited - well, you can hack the class loader.<p>One area where Lisp has been used a lot, is interactive development using so-called images. During development one works with 'images' that contain all the necessary software - that's a part of the 'ball of mud' approach (Smalltalk environments like Squeak work similar and have extensive tools to control that). LispWorks also allows to save preconfigured images - with LispWorks 6 one can dump running programs (with GUI) and restart them later.