Soundplant - Play sound files with the computer keyboard
Ant Media Server - Scalable, Ultra Low Latency & Adaptive WebRTC Streaming Ant Media Server provides Scalable Ultra-low latency (0.5 seconds) Adaptive Live Streaming with WebRTC. It supports RTMP, RTSP, Zixi, WebRTC, Adaptive Bitrate, HLS and MP4 recording.
CasterSoundboard - A soundboard for hot-keying and playing back sounds. (For podcasting)
Red5 - Red5 is an open source Flash media server for live streaming solutions of all kinds.
JN Soundboard - An open-source hotkey soundboard program
MistServer - MistServer is a lightweight, open-source multistandard multimedia server.