On Wed, Aug 18, 2004 at 11:56:11AM +0200, Måns Rullgård wrote: > OK, I forgot to mention those cases where the program includes parts > of itself in the output. However, there is no way an email sent > through postfix can be a work derived from the postfix code. The same > reasons apply here as to compilers. The copyright of object code > produced by a compiler is exactly the same as that of the source > file. Compiling the source code is considered use of the compiler, > and the output is not a work derived from the compiler.
I think it's clear that, in the general case, this "service" class of restrictions goes beyond copyright law, which puts it in the contract license category. I don't know of any use restrictions which we consider free[1], and I'm not aware of any licenses in Debian which form a contract with the user (versus simply granting permissions); I'm very wary of them. I'm also wary of them for other reasons. There's an argument that as no compensation is provided by users, in some jurisdictions it's impossible to form a binding contract, which means that regardless of anything the contract says, the author may be able to take it away at whim as if it had a revocation clause. (I've seen counterarguments like "agreement to warranty disclaimer is compensation", but I'm not yet convinced of that.) http://lwn.net/Articles/60057 and http://lwn.net/Articles/61292 suggest some other possible issues with contract licenses. Finally, I think it's a very useful goal for Debian to be *usable* without having to worry about license conditions. Users should be able to trust that licenses in Debian restrict only distribution, and don't attempt to restrict simple use in any way (which includes, in my mind, using proftpd to distribute my files). By my (poor) understanding, an enforcable copyright license, which by definition can only restrict distribution, can't break this; but contract licenses can. This "service" class of licenses is designed to. [1] I'm not sure if advertising clauses count; they're something like use restrictions (in that they seem to go beyond copyright), but they don't talk about use. -- Glenn Maynard