Microsoft

Microsoft's ambitions are anything but small. The world's #1 software company provides a variety of products and services, including its Windows operating systems and Office software suite. The company has expanded into markets such as video game consoles, servers and storage software, and digital music players. Microsoft has reached settlements to end a slew of antitrust investigations and lawsuits, including agreeing to uniformly license its operating systems and allowing manufacturers to include competing software with Windows. In early 2008 the company made an unsolicited bid to acquire Yahoo! for about $44.6 billion; Yahoo!'s board rejected the bid as "inadequate".

Sun Microsystems

When it comes to network computing, it's hard to find an area where the Sun doesn't shine. Sun Microsystems is a leading maker of UNIX-based servers used to power corporate computer networks and Web sites. It also makes workstation computers and a widening range of disk- and tape-based storage systems. Unlike most hardware vendors, Sun makes computers that use its own chips (SPARC) and operating system (Solaris). Its software portfolio includes application server, office productivity, and network management applications. Sun also developed Java, a programming language for creating software that can run unchanged on multiple operating systems.