RM (Real Media) is a multimedia format developed by RealNetworks. It features a .rm filename extension and is typically multiplexed with RealAudio and RealVideo when streaming content online. The stream is usually in constant bitrate (CBR), although a file container for variable bitrate (VBR) is now available, called Real Media Variable Bitrate (RMVB).
RealNetworks RealPlayer Coud Final Media Player Media Monkey RealTrimmer
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.