[Michael Morris]

The dreaded Halo effect on a GIF. We've all seen it. Switch the background of your forum ever so slightly and prepare to cringe. GIF has served us well, but in the end it's a technology developed when the Commodore 64 was still the most popular computers in the world. It is old technology, and it shows.

GIF is also owned by Compuserve and in the mid 90's they tried to pull the format out from under everyone's feet with trademark lawsuits ad naseum. In this turmoil PNG was developed.

If you're into history read on here (http://www.libpng.org/pub/png/pnghist.html)

In the years that have followed PNG has come to be supported on every major browser to some degree. IE can display PNG's, but it messes the image up horribly if it is 32-bit and has an alpha channel (that is to say, opacity). The thing is, PNG-32 isn't the only variant of PNG. There are two other major branches - PNG-24 which has no transparency or alpha (that I know of) and PNG-8, which does but is limited to a 256 color palette.

PNG-8 has the distinction of quietly working in every major browser - but it's often overlooked because of it's big brother PNG-32. Still, if you want to get rid of GIF's horrid halo effects it's probably the best answer out there since unlike PNG-32 you know it will work in IE6 (and 5 for that matter).

PNG8's are also quite a bit smaller than PNG32's and not noticeably larger than an equivalent GIF. It's worth looking into.