Avast Software /?'v??st, -æst/ is a Czech security software company headquartered in Prague, Czech Republic, that develops antivirus software and internet security services. It was founded by Pavel Baudiš and Eduard Kucera in 1988 as a cooperative and is a private company since 2010. Avast holds the biggest share of the world market for antivirus applications and its portfolio includes a wider array of security-related products targeting both consumer and corporate markets, such as Avast Antivirus and Avast SecureLine (virtual private network) for Android, Microsoft Windows, iOS and macOS platforms. As of 2016, Avast had 400 million users and 40 percent of the security software market outside of China. Avast has over 650 employees based in the Czech Republic, with offices in the United States, Germany, China, South Korea and Taiwan. In September 2016, Avast Software acquired AVG Technologies for US$1.3 billion. After coming across the Vienna virus in 1988, researcher Pavel Baudiš of Prague’s Mathematical Machines Research Institute set to writing a program that would be able to successfully remove it. He then shared the program with his colleague, Eduard Kucera, and later that year the pair started ALWIL Software, which released the first Avast antivirus. Because of restrictions on forming a company in then-Czechoslovakia, ALWIL Software was founded as a cooperative. The Velvet Revolution, however, brought with it the introduction of the free market. In 1991 Baudiš and Kucera were able to register ALWIL Software as a joint-partnership company.