*.OGG

.OGG, or Ogg (see Ogg file format), is a file format for compressed multimedia files and a popular competitor to .MP3. Unlike MP3, Ogg uses an open-source, open-standard format and a permissive license, both of which allow it to be incorporated into the FS2_Open source code. Also unlike MP3, Ogg is a container format, meaning that it can contain video data (via the Theora codec ) in addition to audio data (via the Vorbis codec).

Since Ogg delivers significantly smaller file sizes than .WAV, while retaining substantially the same level of audio quality, it is becoming more and more frequently used in FSO-targeted mods. Ogg is not, however, a lossless format -- i.e., it is not possible to exactly reconstruct the original data from an .OGG file because some is "lost" in the conversion process. This is not usually a problem, however, because a high-quality .OGG file is usually indistinguishable from the source. A popular lossless alternative to Ogg Vorbis is .FLAC.

Audacity and Goldwave are two popular programs that allow .WAV files to be converted to .OGG. Audacity is freeware, while Goldwave is shareware that ceases to function after a period of time.