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.
is a standard for storing audio files in Apple operating systems. It was developed in 1988 based on the IFF format and is a lossless format - audio data is stored in an uncompressed form. In essence, AIFF is an analog to WAV for the Apple Macintosh platform.