Java 2 Platform, Standard Edition (J2SE) software is the premier platform for rapidly developing and deploying secure, portable applications that run on server and desktop systems spanning most operating systems. J2SE 1.5 is a significant release including many new features and updates while preserving compatibility and stability.
Major updates are :- New language updates: Metadata, Generics, Enumerated types, Autoboxing of primitive types New JVM Monitoring and Mangement API Improved out-of-box performance New (but compatible) default Java look and feel For download link go here http://java.sun.com/j2se/1.5.0/download.jsp and for detailed info on changes go here java.sun.com and here J2SE 1.5 in a Nutshell