One of the main reasons Java is so popular is its platform independence, which means that Java programs can be run on many different types of computers. One of the biggest reasons why Java is so popular is the platform independence. Programs can run on several different types of computer; as long as the computer has a Java Runtime Environment (JRE) installed, a Java program can run on it. Most types of computers will be compatible with a JRE including PCs running on Windows, Macintosh computers, Unix or Linux computers, and large mainframe computers, as well as mobile phones. Since it has been around for so long, some of the biggest organisations in the world are built using the language. Many banks, retailers, insurance companies, utilities, and manufacturers all use Java. Steve Zara, a programmer for more than 40 years, describes how there is no sign of Java declining in use. Instead, it is an evolving language which almost uniquely combines stability with innovation. Highlighting the longevity of the language, Zara states that the code you may have written 15 years ago will run on the most up-to-date JVMs and gain the speed advantage of the latest profiling, native code translating, and memory management.