Xvid (formerly 'XviD') is a video codec library following the MPEG-4 video coding standard, specifically MPEG-4 Part 2 Advanced Simple Profile (ASP). It uses ASP features such as b-frames, global and quarter pixel motion compensation, lumi masking, trellis quantization, and H.263, MPEG and custom quantization matrices.
SND is a file extension for a sound file used with a variety of platforms. SND stands for SouND. SND files may contain audio data specific to a Macintosh sound resource (from Mac OS Classic), an AKAI MPC audio sample, a generic Amiga sound, or other audio file. SND files can often be opened by Apple’s Quicktime Player