RA (RealAudio) is an audio format released in 1995 by RealNetworks. It uses multiple audio codecs, including high-fidelity music formats and low-bitrate formats. Since its introduction, the RA format has been mainly used by radio stations to stream audio online. Also, up until 2009, the BBC has been using it to stream sounds online.
RealNetworks RealPlayer Cloud VLC Media Player Wensites with the RealPlayer Plugin
FLAC (Free Lossless Audio Codec) is a free lossless digital audio format developed by Xiph.Org. A compressed FLAC file can be reduced by between 50-70% of the original size and decompress back to the original sound data. This file format supports metadata like ID3 tags, cover art, and album title.