Ogg Vorbis is an open source audio codec developed by the Xiphophorus company. Their website is www.xiph.org/ogg. The codec was designed from the ground up to be an open source alternative to all the proprietary audio codecs out there like MP3 and Real Media. It supports many advanced features such as variable bitrate encoding. It is currently in it's infancy and therefore has a few limitations. Encoders binaries are currently only available for Windows, Linux, and BeOS. It does not, as of this writing, have its own player. Instead it relies on playback plugins that are currently only available for Windows players Winamp and Sonique, MacOS player Audion, and Linux player XMMS. Other limitations include the inability to encode at bitrates lower than 128 kbps and lack of web streaming support. All this will probably change in the future.
After reading on Slashdot that the Ogg plugin and encoder were available I decided to check it out. I was actually very impressed with the results. The Winamp plugin required manual installation (whereas most Winamp plugins use Nullsoft's PiMP installer), but the "installation" meant just moving one file to a certain directory. After installation Winamp plays .OGG files just as well as it plays MP3s. The encoder was simply one executable and one DLL. While the encoder is just a simple command line program, it was very easy to use. All you need to do is type oogenc filename.wav and it will encode the file to a variable bitrate .OGG. If you want to encode at different bitrates you just need to tack on a parameter. My only complaint about the encoder is that it is fairly slow. I usually use Xing's encoder to make MP3s which can encode an MP3 in less than two minutes. The OGG encoder took about 7 minutes to encode a 6 minute song. Then came the real test: A 192 kbps MP3 and a variable bitrate .OGG of the same song going head to head. I think Ogg was the winner. I heard almost no difference between the two files. The .OGG was also about a megabyte smaller.
Considering how young this project is and that it was developed by open source developers and not some major corporation, I believe that Xiphophorus has done an amazing job. Despite drawbacks like slow encoding and lack of platform support, the software is still in beta and can only get better. Unlike VQF et al, Ogg is actually a viable MP3 alternative. I think it will gain popularity, but only if they can achieve more platform support. Since it is open source, that won't be hard.