audio/video streaming, music management, automation, podcast generation, encoding, recording, transcoding, stats generation, etc, etc.
http://www.dlnetworks.net/tools
the quick list
scserv dnas v1/2
liquid soap
ffmpeg
streamtranscoder
eyed3
perl/curl/php/python/html/javascript/shell scripting
htaccess/mod rewrite
api usage (youtube/soundcloud)
crontab