🚀 go-pugleaf

n-reply-to: leisner@sdsp.mc.xerox.com's message of Sun, 5 Feb 1995 18:39:22 GMT

In article <1995Feb5.183922.11557@news.wrc.xerox.com> leisner@sdsp.mc.xerox.com (Marty Leisner 25733) writes:

|   Can I copyleft a changed version of public domain code?
|
|   I suppose the original version is public domain, and the 
|   changed version is copylefted...
---

The answer to your question is "yes".  If the original really was public
domain, then you hold the copyright on your modified version and can
license it any way you like.  The original version, of course, remains
in the public domain (the only way out of the public domain is if it
wasn't really public domain to begin with)).

If the original was *not* public domain, then you still hold a copyright
on your changes to it, but you can only license it in ways consistent
with the licensing of the original.  That is, the modified version is
subject to *both* your license and the original license and may only be
distributed in ways that satisfy both.  You may or may not be able to
distribute your changes on their own (i.e., without the original that
they modify), depending on their relationship to the original, their
independent utility, and other factors; in some cases they may
constitute a derivative work to which both you and the original
copyright holder share copyright.  In such a case you should obtain a
competent legal opinion before distributing - the determination of
how the Copyright Act applies is very sensitive to the details of the
case and unlikely to be a slam dunk one way or the other.

scott

--
scott preece
motorola/mcg urbana design center	1101 e. university, urbana, il   61801
phone:	217-384-8589			  fax:	217-384-8550
internet mail:	preece@urbana.mcd.mot.com