|
|
 |
 |
 | | | | |
 |
|||
 |
||||||
          |
 |
 |
||||
|
Open Source
Java has attracted a lot of interest from the Open Source communities, despite the less than satisfying support for Java on non-Win32 platforms. It is worth noting that the JDK source is available from Sun under various licenses. If you do not intend to use a clean-room Java implementation, and instead you are considering creating a custom version of the Sun VM, it might be worth looking into the licensing details. In general, a deal with Transvirtual will probably give you more freedom at less cost. Free clean-room implementations of Java serve well for research purposes, but are not yet ready for use. Examples include the GNU Japhar JVM at http://www.japhar.org and GNU Classpath core classes at http://www.classpath.org. Both are under the less-restrictive LGPL license and thus they are available for use in commercial products. TYA, at ftp://gonzalez.cyberus.ca/pub/Linux/java, is another interesting project. Other source for Java examples and sources are the GNU/FSF Java repository, at http://www.gnu.org/software/java/java- software.html, the Giant Java Tree at http://www.gjt.org, and the Gamelan Repository at http://www.gamelan.com. In particular, there is the outstanding Java port of the ANTLR parser at http://www.antlr.org, which (like Sun's JavaCC) allows you to create Java parser classes for a given grammar. If you are looking for ways to compile a different language (say, Scheme) to Java bytecode, or you're looking for readily available script interpreters, there is a comprehensive list at http://grunge.cs.tu-berlin.de/~tolk/ vmlanguages.html which might contain your language of choice. Unfortunately, tools for converting C or C++ to Java are not readily available. The C2J and C2J++ conversion tools listed cover only a fraction of the languages. Another noteworthy reference is http://java.sun.com/products/jfc/tsc/tech_topics /generic-listener/listener.html, which provides source to handle runtime-interpreted Java source. You might be skeptical about the relevance of Open-Source solutions and third-party compilers, but remember that id Software's Quake relied on the DJGPP compiler, and that Quake 3: Arena will use a derivative of LCC (see http://www.cs.princeton.edu/software/lcc). Incidentally, such C/C++ compilers could also serve as the starting point for creating your own Virtual Machine. |
|
|
Features
