Warner Bros. Television (WBTV) is the television production arm of Warner Bros. Entertainment, itself part of Time Warner. Alongside CBS Television Studios, it serves as a television production arm of The CW Television Network (in which Time Warner has a 50% ownership stake), though it also produces shows for other networks, such as Shameless on Showtime, The Leftovers and Westworld on HBO (though Time Warner also owns HBO). As of 2015, it is the world's largest television production company measured by revenue and library (along with Sony's Sony Pictures Television). Its most notable TV shows include Friends, ER, The West Wing, Smallville, Supernatural, The Big Bang Theory, and Full House. - Source: Wikipedia