SigmaTel was an American system-on-a-chip (SoC), electronics and software company headquartered in Austin, Texas, that designed AV media player/recorder SoCs, reference circuit boards, SoC software development kits built around a custom cooperative kernel and all SoC device drivers including USB mass storage and AV decoder DSP, media player/recorder apps, and controller chips for multifunction peripherals. SigmaTel became Austin's largest IPO as of 2003 when it became publicly traded on NASDAQ. The company was driven by a talented mix of electrical and computer engineers plus other professionals with semiconductor industry experience in Silicon Hills, the number two IC design region in the United States, after Silicon Valley.