Something I have been wondering is when exactly did SC allow for livecoding? I tried looking at the git history of the JITLib part of the class library on Github but I don’t think that’s an accurate depiction. I know that Julian Rohrhuber figured out the TSpawn trick for hot swapping code in the early 2000’s but that’s about as close as I have come.
Julian can tell you best about JITLib, but just to add: live coding was possible already before JITLib, in SC 2. In 2012 I was surprised by this nice technique, see also Julian’s answer: