RealAudio (.ra)
The RA file extension, short for RealAudio, is an audio format developed by RealNetworks in 1995 for streaming audio over the internet. It was widely used for online radio, music, and speech content, offering efficient compression and support for low-bandwidth connections. RealAudio pioneered real-time audio streaming, contributing to the early evolution of internet media. Though its usage has declined due to modern formats like MP3 and AAC, RA files were instrumental in enabling web-based audio playback before broadband became mainstream.