GCC, the GNU Compiler Collection includes front ends for C, C++, Objective-C, Fortran, Java, and Ada, as well as libraries for these languages (libstdc++, libgcj,...).

Open Watcom is a project of the open source community, with support from Perforce Software, to maintain and enhance the Watcom C, C++, and Fortran cross compilers and tools. An Open Source license from Sybase allows free commercial and non-commercial use of Open Watcom.

GNU Free Fortran 95 -
G95 is a stable, production Fortran 95 compiler available for multiple cpu architectures and operating systems. Innovations and optimizations continue to be worked on. Parts of the F2003 standard have been implemented in g95.

The GNU Fortran project, or gfortran, is developing a Fortran compiler front end, as well as runtime libraries, for GCC, the GNU Compiler Collection. GNU Fortran development is a part of the GNU Project, aiming to bring free number crunching to all GNU system variants. The GNU Fortran development effort uses an open development environment in order to attract a larger team of developers and to ensure that gfortran can work on multiple architectures and diverse environments.

Hugs 98 is a functional programming system based on Haskell 98, the de facto standard for non-strict functional programming languages. Hugs 98 provides an almost complete implementation of Haskell 98, including:

• Lazy evaluation, higher order functions, and pattern matching.
• A wide range of built-in types, from characters to bignums, and lists to functions, with comprehensive facilities for defining new datatypes and type synonyms.
• An advanced polymorphic type system with type and constructor class overloading.
• All of the features of the Haskell 98 expression and pattern syntax including lambda, case, conditional and let expressions, list comprehensions, do-notation, operator sections, and wildcard, irrefutable and `as' patterns.
• An implementation of the Haskell 98 primitives for monadic I/O, with support for simple interactive programs, access to text files, handle-based I/O, and exception handling.
• An almost complete implementation of the Haskell module system. Hugs 98 also supports a number of advanced and experimental extensions including multi-parameter classes, extensible records, rank-2 polymorphism, existentials, scoped type variables, and restricted type synonyms.

Helium is a functional programming language and a compiler designed especially for learning Haskell. It is being developed at the Software Technology group of the Institute of Information and Computing Sciences of Utrecht University in the Netherlands. Quality of the error messages has been the main concern both in the choice of the language features and in the implementation of the compiler. Our goal is to let students (or anyone) learn functional programming more quickly and with more fun.

GHC is a state-of-the-art, open source, compiler and interactive environment for the functional language Haskell.

The Java platform is unique in that it's a software-only platform that runs on top of other hardware-based platforms. Hence, the Java Platform lets you develop and deploy Java applications on desktops and servers, as well as today's demanding embedded and real-time environments. Java also includes classes that support the development of web services and provides the foundation for enterprise development.

Jikes^TM is a compiler that translates Java^TM source files as defined in The Java Language Specification into the bytecoded instruction set and binary format defined in The Java Virtual Machine Specification.

Lua is a powerful, fast, light-weight, embeddable scripting language.Lua combines simple procedural syntax with powerful data description constructs based on associative arrays and extensible semantics. Lua is dynamically typed, runs by interpreting bytecode for a register-based virtual machine, and has automatic memory management with incremental garbage collection, making it ideal for configuration, scripting, and rapid prototyping.'Lua' means 'moon' in Portuguese and is pronounced LOO-ah.