The first personal computer (PC) was called the Altair. Only hobbyists bought this model when it was introduced in 1975. In 1975, college students Bill Gates and Paul Allen formed Microsoft Corporation to develop programs for the Altair. This venture later made Gates and Allen two of the world’s wealthiest men. In 1977, two young Americans began to lay the foundation for the mass-marketed PC. Steven jobs and Stephen Wozniak, the founders of Apple Computer, developed the Apple II. It was less expensive and easier for the average user to understand. Small businesses, families, and schools bought the Apple II for these reasons. Apple scored another success in 1984 with the Macintosh, a powerful, easy-to-use computer. One of the industry’s most important developments occurred in 1981, when International Business Machines (IBM) entered the personal computer market. The model IBM manufactured was more successful than the Apple II, and quickly became the industry standard. Today, personal computers are one of the most popular electronic devices. The machines make quick, efficient data retrieval, manipulation, and storage possible for the everyday user. Computers are also becoming powerful tools for communication and entertainment.