even better, LPC has been rewritten into pike, a general purpose programming language that retains the same capability. in the roxen webserver i can write and reload modules at runtime. this works efficiently because the lifetime of any object instance is limited to each http request. when a module is reloaded http requests already in progress are not affected, only new ones.
in the object storage server open-sTeam also written in pike a more advanced method was developed using proxy objects that can update object references and thus allow the updating of code without breaking the references. i am still using that to host my own websites.
to this day i have yet to find any other language with this power. smalltalk can do it and i believe lisp too, but that's it.