Open Source Virtual Machine Software

The Mozart Programming System is an open source implementation of the programming language Oz 3. Oz is a multi-paradigm language that supports declarative programming, object-oriented programming, constraint programming, concurrency and distributed programming as part of a coherent whole.

Byte Buddy is a code generation and manipulation library for creating and modifying Java classes during the runtime of a Java application and without the help of a compiler. Other than the code generation utilities that ship with the Java Class Library, Byte Buddy allows the creation of arbitrary classes and is not limited to implementing interfaces for the creation of runtime proxies. Furthermore, Byte Buddy offers a convenient API for changing classes either manually, using a Java agent or during a build. In order to use Byte Buddy, one does not require an understanding of Java byte code or the class file format. In contrast, Byte Buddy's API aims for code that is concise and easy to understand for everybody. Nevertheless, Byte Buddy remains fully customizable down to the possibility of defining custom byte code. Furthermore, the API was designed to be as non-intrusive as possible and as a result, Byte Buddy does not leave any trace in the classes that were created by it.

Short for "Metamodel On A Runtime", MoarVM is a modern virtual machine built for the Rakudo Perl 6 compiler and the NQP Compiler Toolchain. MoarVM is used by the majority of Perl 6 programmers. Highlights include: Great Unicode support, with strings represented at grapheme level, dynamic analysis of running code to identify hot functions and loops, and perform a range of optimizations, including type specialization and inlining, support for threads, a range of concurrency control constructs, and asynchronous sockets, timers, processes, and more, generational, parallel, garbage collection, support for numerous language features, including first class functions, exceptions, continuations, runtime loading of code, big integers and interfacing with native libraries. MoarVM provides very little directly - and that's a good thing. It is not tied to a particular way of doing inheritance, roles, mixins, method resolution, type-checking, and so forth.