Altium Limited (formerly known as Protel Systems until 2001) is a publicly traded software company that provides PC-based electronics design software for engineers who design printed circuit boards. Founded as Protel Systems Pty Ltd in Australia in 1985, the company has regional headquarters in the United States, Australia, China, Europe, and Japan. Its products are designed for use in a Microsoft Windows environment and used in industries such as automotive, aerospace, defense, and telecommunications. Its flagship product, Altium Designer, is a software for unified electronics design.