Supported System Configurations for J2SE 5.0 (1.5.0) and Java for Business 5.0 (1.5.0) The configurations listed on this page apply to both the J2SE Development Kit (JDK) and J2SE Runtime Environment (JRE). This chart includes links to the installation instructions followed by the minimum free disk space required before starting installation. Sun also provides the Java for Business product (JFB).