Ensoniq was one of the first companies to do high-fidelity audio on a computer. The were first brought into the bright lights when they were commissioned by Apple Computer to supply the sound synthesis chips for the Apple IIgs line of computers. The first 8-bit sound chip, IIRC.
A favourite of audiophiles and musicians for many years. I know several musicans who still swear by the Ensoniq SoundScape. They also made the fantabulous ASR line of keyboards; a staple of nearly every synthpop band.
Sadly, they began to suffer, and were eventually absorbed into the huge Creative Labs company. They will be missed.