Stands for "Runtime Environment." As soon as a software program is executed, it is in a runtime state. In this state, the program can send instructions to the computer's processor and access the computer's memory (RAM) and other system resources.
When software developers write programs, they need to test them in the runtime environment. Therefore, software development programs often include an RTE component that allows the programmer to test the program while it is running. This allows the program to be run in an environment where the programmer can track the instructions being processed by the program and debug any errors that may arise. If the program crashes, the RTE software keeps running and may provide important information about why the program crashed. When you see the name of a software program with the initials "RTE" after it, it usually means the software includes a runtime environment.
While developers use RTE software to build programs, RTE programs are available to everyday computer users as well. Software such as Adobe Flash Player and Microsoft PowerPoint Viewer allow Flash movies and PowerPoint presentations to be run within the player software. These programs provide a runtime environment for their respective file formats. The most common type of RTE, however, is the Java RTE (or JRE), which allows Java applets and applications to be run on any computer with JRE installed.