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.
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.
X# (pronounced X-sharp) is an XML-oriented programming language designed to quickly create Web applications and services. Everything is represented as an XML tree, and instead of using functions to manipulate information or perform actions, all possible operations are done by adding, removing, or changing nodes from this tree. Since there are no functions to learn and everything is done intuitively, even inexperienced developers can create complex Web applications and services quickly.
AMPC compiles C programs directly into Java bytecode to run on any platform where a Java runtime is available. AMPC can also be used to integrate C and Java programs since AMPC's C functions can directly call numerous Java methods and vice versa. AMPC supports ANSI C 1989 (ISO C 1990). A JNI (JVM Native Interface) feature is available for calling native C or C++ functions. AMPC supports the C standard library as well as TCP/IP, ODBC, and graphics libraries. J2ME CDC 1.1 for mobile devices is also supported.
X-develop is a multi-language, cross-platform IDE from Omnicore. X-develop targets the .NET platform, the Mono platform, and the Java platform. It offers advanced code analysis, project-wide on-the-fly error checking, refactoring, smart editing, fast code navigation capabilities, seamless version control system integration, and other productivity-boosting features for C#, Java, JavaServer Pages, J#, and Visual Basic.NET.