Correction to incorrect legal-status information in GIFLIB

GIFLIB provides a rich set of tools for scripted manipulation of GIF images, and a C library that makes writing custom GIF-manipulating programs easy. For a look at the browseable GIFLIB documentation in HTML, see the GIFLIB home page at http://www.ccil.org/~esr/giflib. The current (3.0) release is available there. In existing releases of GIFLIB I said: "Since it existed before 1 Jan 1995, GIFLIB falls under the grandfather clause in the GIF/LZ licenses of Unisys and CompuServe and may be used without paying royalty fees." I have since been in put in contact with a lawyer at Unisys, and that isn't how they see it. Their position is that because GIFLIB has been modified since 1995 it is not grandfathered, and their patents on the Lempel-Ziv-Welch method mean that commercial use requires a license from Unisys. I have since done more research and dug up a copy of Unisys's licensing FAQ on LZW (published Jan 6 1995). It is now included in the Web-accessible HTML documentation for the package. The policy described in the FAQ specifically exempts "freeware" and non-commercial, non-profit software from the license requirements. Their policy has the usual problems with for-profit *distribution* (for example on source-code CD-ROMs), for which Unisys explicitly says in the FAQ the distributors may be liable. I therefore have to recommend against using GIFLIB at all. In fact, earlier today I was considering entirely withdrawing it from circulation. Having discovered the "freeware" exemption in the FAQ, I no longer believe this is absolutely necessary. But any use of GIFLIB should be approached very carefully, in the realization that it could poison your software if it's distributed in any way Unisys's not-very-clueful lawyers choose to interpret as "for-profit" (the one I exchanged email with didn't know about the freeware exemption). In the slightly longer term, I think it's time for GIFLIB to die and be replaced by a PNG utility toolkit. PNGtools, anyone? There's still a niche for GIF-reading code, but basically just as a GIF-to-PNG converter. Reading GIFs is not really what most of GIFLIB is about; a lot of the utilities define generally useful image transformations that are independent of file format and just happpen to use GIF as an interchange format. These ought to be rescued from patent jeopardy. A lot of the useful utilities in GIFLIB could be saved by throwing out the patented Lempel-Ziv stuff and rebuilding the tools to read and write a minimalist version of PNG (no optional chunks or alpha, at least at first). This would be a good thing, because tools for dicing and slicing PNG images seem to be thin on the ground. Please consider this a solicitation of help for that task. I'm too busy to do it all myself and I'm not really a graphics expert to begin with. Perhaps someone in the PNG community might be interested in leading? -- <a href="http://www.ccil.org/~esr">Eric S. Raymond</a> -- <a href="http://www.tuxedo.org/~esr">Eric S. Raymond</a> "To disarm the people... was the best and most effectual way to enslave them." -- George Mason, speech of June 14, 1788