MythTV is an opensource free media center application has multiple entertainment usage can be used as a personal home theater, network streaming, and digital multimedia entertainment system. MythTV
VLC is a free, Open source, cross-platform multimedia player, supports many audio/video formats, adding subtitles, audio conversion, many user interface skins. and many streaming features.
VLC is free opensource applications for playing multimedia files and working as server for streaming. and there a really cool feature available on this application to convert multimedia