RealNetworks is a provider of Internet media delivery software and services based in Seattle, United States. The company is best known for the creation of RealAudio, a compressed audio format, RealVideo, a compressed video format, RealPlayer, and for its leadership in the field of streaming media.
RealMedia audio streaming files can contain RealAudio and RealVideo streams, and several other formats like SMIL. Helix is RealNetworks' open source media framework. The code is released under various licenses, like the RealNetworks Public Source License starting in 2003 and the GPL in 2004. Not all of the source code is licensed under the GPL license, in particular the codecs.