Three years ago, I contacted UNISYS for a license to use GIF technology in some educational freeware I was writing for a class I teach. The software would be given to the students, who could then export the results of their work as GIFs to post to the class web site. The only terms under which Unisys would license the LZW patent for this use was if my university made an open-ended commitment to pay Unisys $5.00 for every copy of the software distributed. I pointed out that the accounting overhead of keeping records would surely cost more than the license fees (which would amount to about $200 a year). I had some money from a grant for developing the class and proposed to pay them a flat fee, but no, it was a per-unit fee or nothing, so I got LibPNG and haven't looked back. On the other hand, UNISYS was willing to give me a free license to use a GIF-generating program on a web server for an interactive web-based lab exercise for this class, so long as the software itself was not distributed. All in all, the faster we move to PNGs the better! However, it's worth noting that the MNG spec for animated PNGs is not yet supported by most browsers to the best of my knowledge, so your advertisers will still want their animated banner ads to be GIFs

Are there any intellectual property issues around Zlib (http://www.info-zip.org/pub/infozip/zlib/)? The ZLib license gives explicit permission to use with commercial software with almost no restrictions. There are no GPL-like issues that require you to give away your own code or even to supply the customer with Zlib source. You do not even need to mention ZLib in connection with your product. The algorithms in Zip have been carefully researched to be patent-free, which is why PNG, which uses ZIP compression is being promoted as a royalty-free alternative to GIF. Zlib is also an official part of the Java JDK 1.1: it is the engine used to compress Java JAR files and is present as a class in the core Java library. I would point out that ZLib is so good that Dundas's competitors Stingray simply include an outdated version of the free ZLib as the compression engine for their Objective Toolkit and Objective Toolkit Pro. I trust that Dundas has more class than that. Sometimes the tech support you get with a commercial library is definitely worth the price, but unless I am missing something here, I don't think the intellectual property issues are as great a concern as you suggest

In an equally useful poll, 8-32 was chosen as the best screw thread, narrowly beating out M3