Multi-Platform StreamingMedia player.
Made by RealNetworks.
Many people have opinions about it.
Actually a TrojanHorse. See these and more:
Real Networks also Bundles the CometCursor adware with RealPlayer.
Despite the fact that a great deal of desirable content is only available in proprietary Real formats, I would never consider installing software from a company whose disregard for privacy is so blatantly criminal. Stick to companies whose true customers are the users -- software funded by advertisement and marketing schemes is dangerous and shady. Unless you want them to consider it a date, DontLetOthersPayForYourDinner.
Use OggVorbis.