Excelsior JET is a Java VM enhanced with an Ahead-Of-Time (AOT) compiler and deployment toolkit. It is certified Java Compatible on Windows and Linux on Intel x86 hardware. The 64-bit version is in the works. Excelsior JET Optimizer transforms your classes and JARs into high-performance binary executables. Excelsior JET Runtime includes a licensed Sun implementation of the Java API and Excelsior's proprietary JVM, which is responsible for Java memory management, threading, synchronization, security, and JIT compilation of classes that could not be precompiled. The Excelsior JET Installation Toolkit makes it possible to prepare your optimized application for deployment to end-user systems.
JCPP is a complete, compliant, standalone, pure Java implementation of the C preprocessor. It is intended to be of use to people writing C-style compilers in Java using tools like sablecc, antlr, JLex, CUP, and so forth. It has been used to successfully preprocess much of the source code of the GNU C library.
Jikes RVM (Research Virtual Machine) provides a flexible open testbed to prototype virtual machine technologies and experiment with a large variety of design alternatives. Jikes RVM runs on many platforms and advances the state-of-the-art of virtual machine technologies for dynamic compilation, adaptive optimization, garbage collection, thread scheduling, and synchronization. It is self-hosted, i.e. its Java code runs on itself without requiring a second virtual machine. Most other virtual machines for the Java platform are written in native code (typically C or C++). A Java implementation provides ease of portability and a seamless integration of virtual machine and application resources such as objects, threads, and operating-system interfaces.
ANTLR (ANother Tool for Language Recognition) is a language tool that provides a framework for constructing recognizers, compilers, and translators from grammatical descriptions containing C++, Java, or Sather actions. It is similar to the popular compiler generator YACC, however ANTLR is much more powerful and easy to use. ANTLR-produced parsers are not only highly efficient, but are both human-readable and human-debuggable (especially with the interactive ParseView debugging tool). ANTLR can generate parsers, lexers, and tree-parsers in either C++, Java, or Sather. ANTLR is currently written in Java.
Scala is a modern multi-paradigm programming language designed to express common programming patterns in a concise, elegant, and type-safe way. It smoothly integrates features of object-oriented and functional languages including mixins, algebraic datatypes with pattern matching, genericity, and more. It is well integrated with Java and .NET: the Scala compiler produces standard Java class files or .NET assemblies, and Java/.NET libraries and frameworks can be used without glue code or additional declarations.
SableCC is a parser generator that generates fully featured object-oriented frameworks for building compilers, interpreters, and other text parsers. In particular, generated frameworks include intuitive strictly-typed abstract syntax trees and tree walkers. SableCC also keeps a clean separation between machine-generated code and user-written code, which leads to a shorter development cycle.
J2ObjC is a tool from Google that translates Java code to Objective-C for the iOS platform. It enables Java code to be part of an iOS build, as no editing of the generated files is necessary. The goal is to write an app's non-UI code (such as data access or application logic) in Java, which can then be shared by Web apps using GWT, Android apps, and iOS apps. J2ObjC supports most Java language and runtime features required by client-side application developers, including exceptions, inner and anonymous classes, generic types, threads, and reflection. JUnit test translation and execution are also supported.