On Fri, 2007-11-02 at 07:40 -0400, Tom "spot" Callaway wrote: Answer: Free, and GPL compatible as long as the copyright holder is Eric Allman, Sendmail Inc, or the University of California. ~spot

(IAARHL, TINLA) On Tue, Mar 25, 2008 at 04:53:48PM +0100, Nils Philippsen wrote: Not really, but here's the explanation. The sendmail license was drafted by Eric Allman with (among other things) the intent of making it GPL-compatible. However, the clause in question does not clearly achieve that effect. It says you can redistribute, even for profit, provided: Redistributions are accompanied by a copy of the Source Code or by an irrevocable offer to provide a copy of the Source Code for up to three years at the cost of materials and delivery. Such redistributions must allow further use, modification, and redistribution of the Source Code under substantially the same terms as this license. It is not clear from a literal analysis how to interpret that second sentence, but one could argue that if you incorporate sendmail code into a larger GPL-licensed work, there are licensing terms governing subsequent distribution of the whole which are no longer "substantially the same terms" as those of the sendmail license. (For example, sendmail permits binary-only distribution, whereas the GPL requires that the recipient of a binary be provided with complete corresponding source code.) There's enough evidence to satisfy me that Eric Allman didn't intend that interpretation. I think it is reasonable to consider Eric Allman and Sendmail, Inc. licensing alter egos for purposes of this analysis. As for the University of California, there's a 3-clause BSD-like license embedded in the Sendmail license that applies to portions copyrighted by UC. If some third party licensor started using this license for some other code, I don't think you could assume they'd share the view of Eric Allman that the clause in question was designed to facilitate GPL compatibility. Indeed, the best literal reading of the clause leads to the opposite conclusion. Licenses are generally interpreted according to the intent of the licensor. I think this might take care of all code in sendmail that is actually covered by the Sendmail license, but I haven't checked closely. -- Richard E. Fontana Red Hat, Inc.