What is it?
RealPlayer Automation Interface is part of RealPlayer, by RealNetworks, a cross-platform software product primarily used for the playing of recorded media. The media player is compatible with numerous formats within the multimedia realm, including MP3, MPEG-4, QuickTime, Windows Media, and multiple versions (proprietary) of RealAudio and RealVideo formats.
Description of ierpplug.dll from RealNetworks
“Real brings you RealPlayer, the only solution you’ll need for managing all your music and videos. It’s the best free media player around for enjoying all types of entertainment! You can also transfer your media to and from your PC and mobile phone. With the RealPlayer media player, you can play files created for both MAC and PC, as well as the following types of files: m4a, mp3, wma, ra, rv, rm, ram, rmvb, wav, flv, 3gp, 3gp2, mp4, m4v, wmv, iv4, avi, MPEG-4, and more.”