GL4Java is an OpenGL language mapping for Java by Sven Goethel. What it does is allow the programmer to call OpenGL functions from within Java. For the user this means that it is possible to view 3d rendered scenes in a web browser or native Java window/frame. GL4Java is licenced under the LGPL(Library General Public License).
Although conceptually one would think that performance would be lacking since Java bytecode must be interpreted by a virtual machine, the calls are actually made natively through the JNI(Java Native Interface) to the users' native OpenGL library. GL4Java is composed of two layers, the Java classes, and the native library. Performance depends on the implementation of the JVM(Java Virtual Machine) that the user is running, and the implementation of OpenGL that he has on his machine(as well as hardware and program logic, but those factors are beyond the control of GL4Java). Since the calls are native, rendering is done as with native OpenGL applications-either through software or hardware.
Other 3D API's that map OpenGL to Java were provided by Magician and JSparrow, both now defunct(and notably proprietary/closed-source). Other solutions for providing 3D in web browsers include VRML and Metastream. Sun has it's own 3D API, called Java 3D, which has support for both OpenGL and Microsoft's DirectX. It is not exactly a mapping of the API's, rather it is a higher level API built on top of OpenGL or DirectX.
GL4Java currently supports various Unices such as Linux, Solaris, IRIX, the Windows series of operating systems, as well as Macintosh OS 9x and OS X. Of course, the GL4Java libraries must be present on the user's system if he wants to be able to run a GL4Java applet. The user can install directly from the web site through a Java applet, download a standalone version of the installer which then downloads and installs the required files, or download all the required files and install them manually. The ease of installation is very important to promote support for the API.
Applications using GL4Java include Arkane, a 3D 1st/3rd person perspective RPG, an .MD3 model viewer, Tetris 3D, and more can be found on the website. Visit the website and check out the demos.
The website is located at: www.jausoft.com/gl4java
Gothel, Sven. Jausoft GL4Java Home-Page. www.jausoft.com/gl4java. Jausoft. April 28, 2002
java.sun.com - The Source for Java(TM) Technology. java.sun.com. Sun Microsystems Inc. April 28, 2002
Arkane. arkanae.tuxfamily.org. April 28, 2002
Update: Apr. 29, 2002
Formalized source citations.
Removed the "and more..." from the end of the feature list.