javac is the primary Java compiler

Java compiler

A Java compiler is a compiler for the Java programming language. The most common form of output from a Java compiler is Java class files containing platform-neutral Java bytecode...

, included in the Java Development Kit

Java Development Kit

The Java Development Kit is an Oracle Corporation product aimed at Java developers. Since the introduction of Java, it has been by far the most widely used Java SDK. On 17 November 2006, Sun announced that it would be released under the GNU General Public License , thus making it free software...

 (JDK) from Oracle Corporation

Oracle Corporation

Oracle Corporation is an American multinational computer technology corporation that specializes in developing and marketing hardware systems and enterprise software products – particularly database management systems...

.

The compiler accepts source code conforming to the Java language specification

Java (programming language)

Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...

 (JLS) and produces bytecode

Java bytecode

Java bytecode is the form of instructions that the Java virtual machine executes. Each bytecode opcode is one byte in length, although some require parameters, resulting in some multi-byte instructions. Not all of the possible 256 opcodes are used. 51 are reserved for future use...

 conforming to the Java Virtual Machine

Java Virtual Machine

A Java virtual machine is a virtual machine capable of executing Java bytecode. It is the code execution component of the Java software platform. Sun Microsystems stated that there are over 4.5 billion JVM-enabled devices.-Overview:...

 Specification (JVMS).

javac is itself written in Java

Java (programming language)

Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...

. The compiler can also be invoked programmatically.

History

On 13 November 2006, Sun's Java Virtual Machine (JVM)

Java Virtual Machine

A Java virtual machine is a virtual machine capable of executing Java bytecode. It is the code execution component of the Java software platform. Sun Microsystems stated that there are over 4.5 billion JVM-enabled devices.-Overview:...

 and Java Development Kit (JDK)

Java Development Kit

The Java Development Kit is an Oracle Corporation product aimed at Java developers. Since the introduction of Java, it has been by far the most widely used Java SDK. On 17 November 2006, Sun announced that it would be released under the GNU General Public License , thus making it free software...

 were made available under the GPL license (see Sun's OpenJDK Hotspot page).

Since version 0.95, GNU Classpath

GNU Classpath

GNU Classpath is a project aiming to create a free software implementation of the standard class library for the Java programming language. Despite the massive size of the library to be created, the majority of the task is already done, including Swing, CORBA, and other major parts. The Classpath...

, a free implementation

Free Java implementations

Free Java implementations are software projects that implement Oracle's Java technologies and are distributed under free software licences, thus making them free software...

 of the Java Class Library

Java Class Library

The Java Class Library is a set of dynamically loadable libraries that Java applications can call at run time. Because the Java Platform is not dependent on any specific operating system, applications cannot rely on any of the existing libraries...

, supports compiling and running javac using the Classpath runtime

Run-time system

A run-time system is a software component designed to support the execution of computer programs written in some computer language...

 (GIJ

GNU Interpreter for Java

The GNU Interpreter for Java is a Java bytecode interpreter for the Java programming language.It is part of the free software GNU Compiler for Java . GCJ is the compiler counterpart to GIJ.-External links:* * *...

) and compiler (GCJ), and also allows one to compile the GNU Classpath

GNU Classpath

GNU Classpath is a project aiming to create a free software implementation of the standard class library for the Java programming language. Despite the massive size of the library to be created, the majority of the task is already done, including Swing, CORBA, and other major parts. The Classpath...

 class library, tools and examples with javac itself.

See also

• Java compiler
  Java compiler
  A Java compiler is a compiler for the Java programming language. The most common form of output from a Java compiler is Java class files containing platform-neutral Java bytecode...
  
   for a general presentation of Java compilers, and a list of other existing alternative compilers.
• Java (programming language)
  Java (programming language)
  Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...
  
  
• Java Platform
• OpenJDK
  OpenJDK
  OpenJDK is a free and open source implementation of the Java programming language. It is the result of an effort Sun Microsystems began in 2006...
  
  

External links

• Sun's OpenJDK javac page
• The Java Virtual Machine Specification
• JSR 199 Java Compiler API Java Specification Request for invoking the Java compiler from a Java program