Every Java application has a single instance of class Runtime that allows the application to interface with the environment in which the application is running. End user running Java on a desktop: JRE: (Java Runtime Environment). 8 demos and samples are included in the JDK 8 Demos and Samples packages. Java SE - Downloads - Java Runtime Environment - Server JRE (Java SE Runtime. Trying to install the Java SE Runtime Environment on a non-supported version of up-to-date Service Pack will cause the installer to generate this warning: "We..