SMPlayer is a free open source media player that can play virtually all video and audio formats with its built-in codecs: AVI, MP4, MKV, MPEG, MOV, WMV, MP3, WAV, AAC, AC3, M4A, WMA... It doesn't need any external codecs.

SMPlayer can also play, search and download Youtube videos. It can find and download subtitles from opensubtitles.org as well. It includes a thumbnail generator that allows to create an image with preview thumbnails of the video. One of the most interesting features is its capability to resume playback, so if you start to watch a movie but you have to leave... don't worry, when you open that movie again it will be resumed at the same point you left it.

This program is for those that want a powerful media player that can play all formats out of the box, and don't want to waste their time looking for codec packs. It will be also very useful for those who want to download Youtube videos easily.