trx is a toolset for broadcasting live audio from Linux. It sends and receives encoded audio over IP networks, via a soundcard or audio interface, and can be used for point-to-point audio links or multicast (e.g., private transmitter links or audio distribution). High-quality wideband audio (such as music) can be sent with low latency and fast recovery from dropouts.
SMPlayer is a complete media player for Windows and Linux. It uses MPlayer as a playback engine, which is capable of playing most video and audio formats (AVI, mkv, WMV, MP4, MPEG, etc.). It can also play and download YouTube videos. One of the most interesting features is that it remembers the settings of all files you play. So if you start to watch a movie but have to leave, when you open that movie again it will resume at the same point you left it, and with the same settings: audio track, subtitles, volume, etc.