Vista Codec Package software (version 6.4.4) is a collection of codecs and filters that allow users to play audio and video files on their Windows Vista operating system. The software supports a wide range of file formats including MP4, AVI, and MKV. It also includes advanced features such as support for subtitles, playback control, and graphic equalization. Additionally, the software is regularly updated to ensure compatibility with the latest codecs and file formats.