Posted on March 24, 1999 at 8:28:27 PM Central.

Comments about the AT&T Source Code License

Last week AT&T Research released much of the source code to their DjVu image compression library under the AT&T Source Code License. This license has many interesting features, some of which bother me. Below are some (edited) comments about the license that I sent to AT&T. I got an email from someone on the DjVu team thanking me for the comments, so they're definitely listening.

It isn't clear to me how the license would affect code written in another language (e.g. Java) that uses algorithms and ideas from the reference library but no actual code. I think this would be considered a derivative work, but distributing Java source files as a patch against some C++ code seems impractical; the source trees wouldn't have anything in common. In fact, section 3.4 seems to preclude alternate implementations that contain no AT&T code. This is reminiscent of the 60% clause in the Jikes license.

Section 3.3 of the license is distasteful, because it doesn't refer to the actual software. I also assume that it isn't strictly necessary to mention such matters in the license, since AT&T's trademarks are presumably already adequately protected.

Section 7.2 is a problem, because my rights to use the source could vanish at any moment. I would prefer that the unenforceable parts of the license simply be nullified with the rest continuing to hold, as in Apple's APSL.

Wesley Felter, not a lawyer