Z:gnu-www-ja-google-engineering-talk--5f2e22-=3Cb=3ERICHARD:=3C/b=3E Well, of the p/en

RICHARD: Well, of the popular file formats, the only ones that I know of that are secret are some Microsoft ones. But, on the other hands, there are others that have patent problems. For instance, there's still a patent covering LZW compression, which is used in GIF format. And someone has a patent he claims covers JPEG format and is actually suing a bunch of companies. And then there's a patent on MP3 audio, so that the free software MP3 encoders have been driven underground in the US. That's why people should switch to Ogg Vorbis format. And then, if you look at, say, MPEG-2 video, there are 39 different US patents said to cover aspects of MPEG-2. So there are a lot of such problems.