PNG [pronounced "ping"? is the Acronym for Portable Network Graphics, a new, losslessly compressed bitmapped graphics format. It is approved by the World Wide Web consortium as the successor of the GIF format. The latter depends on a compression algorithm called LZW which was patented by Unisys long ago. In contrast, PNG relies on the patent free LZSS algorithm for compression and is completely unencumbered with licensing fees. Recent versions of Mozilla, Opera, and Microsoft InternetExplorer support PNG, although the latter doesn't support alpha channels. (Rumour has it that the IE engine is too old and out of date to support transparency without lots of hideous hacks. Amusingly, while Microsoft can't make these hideous hacks, we can.)