For the record, the .gifs I've generated for this use liscensed code (by Macromedia), so are legally safe from patent infringement.
Personally, I like the idea of using PNGs, but am not certain of how well implemented PNG interpretation is in current browsers.
I think the GIF issue parallels the differences between opensource (tolerant to mixed use of intellectually protected technologies and Free Software movement) versus GNU (pure nonprotected/nonliscensed technologies only). OpenACS.org has chosen the mixed use path since it optionally uses Oracle and Microsoft Windows etc. Therefore, the issue seems mute here as a matter of practice.
