Java & JDK -- a powerful object oriented language and development environment.
Java Home Page
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Java FAQ .jp ( What's New )
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Albert Bailey -- Java Tools
The Java Oasis
EspressoGrinder: for the quick Java kick!
Espresso
http://www.webcity.co.jp/info/andoh/java/j2uc/
teikade information base

Java Linux ( JDK for Linux, etc. )

Java-Linux (新しいURL)
Java-Linux

JOLT -- a freely available and redistributble implementation of Sun's Java language and tools.

JOLT Project Home Page

Kaffe -- a virtual machine design to execute Java bytecode.

Guavac -- a standalone compiler for the Java programming language.

Harissa -- a compiler from Java bytecode to C and a Java interpreter.

JUMP -- a bytecode compiler to compile JAVA source code.

Japhar -- the Hungry Programer's Java VM.

Japhar - The Hungry Java Runtime

TYA -- a '100% inofficial' JIT-compiler for Linux (x86).

TYA Archive

PIZZA -- a substantial companion to Java.

Java Developer Tools (IBM technology preview)

Java Compiler Compiler (JavaCC) - The Java Parser Generator

DashO(tm) - Java Code Optimizer

Jad -- a fast Java decompiler.

Jasmin -- a Java assembler interface.

Java(tm) Bytecode Assembler

jas -- a Java bytecode assembler.

j2c -- a translator from java .class to C program.

Toba -- a Java-to-C translator.

JCC -- a Java to C converter

JPP -- a preprocessor for the Java language

Snacc -- A Java stub compiler for ASN.1 specifications.

NetRexx -- a human-oriented programming language designed to be an alternative to Java.

Juice -- an alternative to Java.