Coherent GT - Fast user interface runtime for PC and Consoles
FMOD - FMOD Studio is an audio middleware solution and engine for games.
Sciter - Embeddable HTML/CSS/script engine
Wwise - Game audio engine, designed to give artists more control and save programmers' time.
Ultralight - Fast, light HTML UI solution for C++ apps
SoLoud - Easy to use, free, portable c/c++ audio engine for games.