If the Java platform is to be language neutral, the key would have to be Java bytecode (JBC). The Java-language architecture requires that Java source code be translated to JBC before being compiled or interpreted. In theory, any language that can translate to JBC should be usable within the Java platform. This brings us one step forward. If we take any language and let it produce JBC, we have what we want.

Programming Languages for the Java Virtual Machine
As you can see on http://grunge.cs.tu-berlin.de/~tolk/vmlanguages.html, there are currently about 160 different systems. Be careful since this list is a mix of both experimental, research-oriented implementations and commercial ones. However, this list contains only languages in which the source code of a program executed in the Java VM has a syntax that's different from Java's.

The following is a partial list of programming languages, the language's port, and a brief description for the Java Virtual Machine.

Ada
JGNAT Ada 95
The JGNAT system offers a complete Ada 95 development environment for the Java platform. JGNAT is made up of a compiler that generates Java bytecode that's compatible with Java Virtual Machines conforming to Sun's standard (JDK 1.1 and above), and a set of tools to aid in developing Ada programs for the Java platform.

Assemblers
Javaa
The Java Bytecode Assembler is a program that converts code written in "Java Assembly Language" into a valid Java .class file.

Jasmin
Jasmin is a Java Assembler Interface. It takes ASCII descriptions for Java classes that are written in a simple assembler-like syntax and use the Java Virtual Machine instruction set. It converts them into binary Java class files suitable for loading into a Java interpreter.

Jas
Jas is a Java bytecode assembler. Java bytecode can be generated through a script that drives the assembler package or directly through the assembler package from Java. The assembler package is very simple - it doesn't attempt to validate or optimize bytecode.

Basic
Convert
With Convert 1.1 you can use your Visual Basic expertise to create high-powered, sophisticated Java applets and applications. Convert 1.1 is a GUI converter; your VB screens are translated directly into Java source code.

JBasic
JBasic is an embeddable BASIC interpreter written entirely in Java. It's designed for scripting JavaBeans at runtime. You can embed JBasic in any Java application, applet, or bean using the JBasic Runtime Engine. (Note: I've received an e-mail from Mike Lehman that refers to some legal information that this is not the first embeddable Basic - if you care about such important notionsŠ.)

JavaBasic This is a command-line interpreter that loosely uses the BASIC command set.

COCOA
The Java BASIC Interpreter is a simple BASIC interpreter written in Java. It's a primitive BASIC, uses line numbers, and implements most of BASIC-80.

TRS-80 Model 1 BASIC Interpreter
This applet is an interpreter for TRS-80 Model 1 Level 2 BASIC. Note that it is a BASIC interpreter, not a TRS-80 emulator; thus, the hardware-specific commands (PEEK, POKE, etc.) don't work.

Applet Designer
A Visual Basic add-in, it converts new or existing VB applications into Java applets.

COBOL
PERCobol Enterprise Edition
This is a robust COBOL development solution that enables COBOL programs to execute on the Java Virtual Machine. PERCobol is a fully ANSI 1985 X3.23b standard-compliant COBOL compiler that generates Java source code. The resulting code can then be compiled using any JDK 1.1+ compliant Java compiler and will run on any JDK 1.1+ implementation of the JVM as either an applet or application, depending on how the program is invoked (applets are subject to applet security restrictions).

Eiffel
J-Eiffel
An Eiffel-to-Java compiler is an Eiffel compiler with JVM bytecode generation.

Project Bruce
Translating from Eiffel to Java, this was a collaborative project between the Microsoft Research Institute at Macquarie University in Sydney, Australia, and Interactive Software Engineering (ISE), and was aimed at developing an Eiffel-to-Java compiler.

Forth
myForth
A basic Forth interpreter written in Java, Forth programs can be read from Java applet parameters.

DELTA Forth
A new Forth dialect that's intended to bring the Forth programming language to the Java universe. Unlike Forth, DELTA Forth is a compiled language. This means that the source code is turned into a special format that's used to execute the program.

Lisp
SISC
An extensible Java-based interpreter of the algorithmic language Scheme, SISC is a complete implementation of the language. The entire R5RS Scheme standard is supported. SISC can also interface with Java through a bridge module called J2S.

Lisp
This is a small Lisp implementation in Java.

PS3I
The Persistent Server-Side Scheme Interpreter is almost an R4RS-compliant scheme implementation written in Java. It is multiuser, multithreaded, and aimed to run on (Web-)servers (as servlets).

Logo
AJLogo
AJLogo is an implementation of Logo written in Java with about 400 primitives.

Turtle Tracks
A modern Logo interpreter and runtime environment written entirely in Java, it's not a direct port of an existing interpreter, but is written from the ground up specifically for Java, and designed to take advantage of the strengths of Java as a platform. It supports numerous advanced features such as multithreading and networking. It's a complete implementation of true Logo, supporting the same basic language syntax and semantics and most of the same primitives as other common Logo implementations, such as Berkeley Logo. It also supports plug-in primitive sets and can be integrated with outside Java code as a scripting language.

Smalltalk
SmalltalkJVM
This compiler allows Smalltalk to run on any JVM. The compiler currently produces 100% Java class files that are fully compatible with the Sun JVM specification. This allows Smalltalk and Java code to interact seamlessly and allows Smalltalk programs to run anywhere Java runs.

Talks2
A full Smalltalk development environment, it runs on top of the Java Virtual Machine. It includes a ClassBrowser, Workspace, Transcript, and all the things you know from a Smalltalk Development Environment. Talks2 translates Smalltalk to Java, and also uses the Java GUI and IO to run in any regular Java environment.

Bistro
A new programming language that integrates features of Smalltalk and Java, Bistro is a variation of Smalltalk that runs on top of any JVM that conforms to Sun's Java specifications. Bistro offers Smalltalk developers a way to reuse the models they built with Smalltalk. Bistro provides mechanisms for translating Smalltalk model code into Java, so that models originally built with Smalltalk may be deployed on and execute in a Java environment.

Scripting
JRuby
JRuby is the effort to re-create the Ruby interpreter in Java. Currently, the interpreter is written in C. The Java version will be tightly integrated with Java to allow you to script any Java class and to embed the interpreter into any Java application.

JPython
JPython is an implementation of the object-oriented scripting language Python, and is seamlessly integrated with the Java platform. It features high-level built-in data types, dynamic typing, packages, classes, and interactive compilation to Java bytecodes.

Jython
Jython is an implementation of Python, the high-level, dynamic, object-oriented language written in 100% Pure Java, and is seamlessly integrated with the Java platform. Thus it allows you to run Python on any Java platform. Jython is the successor to JPython.

Tcl
Jacl
Pronounced "Jackal," Jacl is a Tcl interpreter written in Java. You can use it for Java the same way Tcl is used for C - a scripting language to glue together modules written in a low-level language.

Jython with EAServer
I'd like to focus briefly on Jython as it's freely available for both commercial and non-commercial use and is distributed with source code. Jython complements Java and is especially suited for the following tasks:

Conclusion
As we saw, there are a lot of interesting languages out there worth looking at. Many of them can be used in your own client/server or EAServer projects. I agree that some of them are still "under development," but a lot are worth looking at. This article should show you that the Sybase slogan is true - "Everything works better, when everything works together" - we just have to open our minds and our eyes.

Software Used

Resource