The official player for RealMedia content is RealNetworks' RealPlayer SP, currently at version 16, and is available for various platforms in binary form.
Several features of this program have proven controversial (most recently, RP11's ability to record unprotected streaming media from web sites), and many alternative players have been developed.
RealNetworks initially tried to discourage development of alternative players by keeping their audio format secret.
As these formats had been described in detail in various technical papers and standards documents, it was possible to write software capable of playing RealAudio based on this information.
However, Real Alternative does not decode the audio data by itself, but relies on the dynamically linked libraries (DLLs) from the official RealPlayer.
The audio codecs in ffmpeg were written based on the publicly available information about the formats, and do not use the RealPlayer or Helix software.
The first version of RealAudio used a proprietary protocol called PNA or PNM to send streaming audio data.
Other programs, including MPlayer, RM Downloader, VLC media player, StreamBox VCR, HiDownload and Real7ime Converter can also save streams to a file.
The development of RealAudio by Progressive Networks in the mid-1990s enabled efficient streaming of audio content over the internet.
While details about the specific features are limited due to the archived nature of the website, it likely offered functionalities such as artist selection and genre browsing.
The concept of on-demand music access, popularized by this website, laid the groundwork for the development of future industry giants like Spotify and Pandora.