History of Java language

Java is a programming language created by James Gosling from Sun Microsystems (Sun) in 1991. The target of Java is to write a program once and then run this program on multiple operating systems. Java is defined by a specification and consists of a programming language, a compiler, core libraries and a runtime. Java programming language which still runs on the Java virtual machine. The Java platform is usually associated with the Java virtual machine and the Java core libraries.

• From the first version released in 1996. 
• Versions 1.0 are named as JDK (Java Development Kit). 
• From versions 1.2 to 1.4, the platform is named as J2SE (Java 2 Standard Edition). 
• From versions 1.5, Sun introduces internal and external versions. Internal version is continuous from previous ones (1.5 after 1.4), but the external version has a big jump (5.0 for 1.5). 

Version Name	Code Name	Release Date
JDK 1.0	Oak	January 1996
JDK 1.1	(none)	February 1997
J2SE 1.2	Playground	December 1998
J2SE 1.3	Kestrel	May 2000
J2SE 1.4	Merlin	February 2002
J2SE 5.0	Tiger	September 2004
Java SE 6	Mustang	December 2006
Java SE 7	Dolphin	July 2011
Java SE 8		March 2014
Java SE 9		September, 21st 2017
Java SE 10		March, 20th 2018
Java SE 11		September, 25th 2018

Since Java SE 11,  new versions will be released very six months.

The Java language have following properties:

• Platform independent: A Java program can run unmodified on all supported platforms, e.g., Windows or Linux.
• Object-orientated programming language: Except the primitive data types, all elements in Java are objects.
• Strongly-typed programming language: Java is strongly-typed, e.g., the types of the used variables must be pre-defined and conversion to other objects is relatively strict, e.g., must be done in most cases by the programmer.
• Interpreted and compiled language: Java source code is transferred into the bytecode format which does not depend on the target platform. These bytecode instructions will be interpreted by the Java Virtual machine (JVM).
• Automatic memory management: Java manages the memory allocation and de-allocation for creating new objects. The program does not have direct access to the memory.

The Java syntax is .java. Java is case-sensitive.

// a small Java program
public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello World");
    }
}