Microsoft was founded by Bill Gates and Paul Allen on April 4, 1975, to develop and sell BASIC interpreters for Altair 8800. It rose to dominate the personal computer operating system market with MS-DOS in the mid-1980s, followed by Microsoft Windows. The company's 1986 initial public offering, and subsequent rise in its share price, created three billionaires and an estimated 12,000 millionaires from Microsoft employees. Since the 1990s, it has increasingly diversified from the operating system market and has made a number of corporate acquisitions. In May 2011, Microsoft acquired Skype Technologies for $8.5 billion in its largest acquisition to date.
Zscaler is a global cloud-based information security company that provides Internet security, web security, next generation firewalls, sandboxing, SSL inspection, antivirus, vulnerability management and granular control of user activity in cloud computing, mobile and Internet of things - centric environments. As of 2015, Zscaler provides automated threat forensics and dynamic malware protection against advanced cyber threats, such as advanced persistent threats and spear phishing for more than 6,000 corporate, government and military organizations with more than 15 million paying users.