A practical lambda-calculator is a normal-order evaluator for the untyped lambda-calculus, extended with convenient commands and shortcuts to make programming in it more productive. Shortcuts are distinguished constants that represent terms. Commands define new shortcuts, activate tracing of all reductions, compare terms modulo alpha-conversion, print all defined shortcuts and evaluation flags, etc. Terms to evaluate and commands are entered at a read-eval-print-loop (REPL) "prompt" or "included" from a file by a special command. A Haskell branch is an embedding of the lambda calculator (as a domain-specific language) into Haskell. The calculator can be used interactively within Hugs or GHCi.
AFNIX is a multi-threaded functional writing system with dynamic symbol bindings that support the object oriented paradigm. It has a rich set of features providing runtime compatibility with C++. The engine runs on both 32- and 64-bit platforms, and it is designed to be portable across platforms.
AI::Prolog is a predicate logic engine implemented in pure Perl. In predicate logic, instead of telling the computer how to do something, you tell the computer what something is and let it figure out how to do it. Conceptually, this is similar to regular expressions. The AI::Prolog distribution contains a Prolog shell called aiprolog and two short adventure games, spider.pro and sleepy.pro.
AMC is a programmable compiler/preprocessor. It has a built-in programming language called CGL (Code Generation Language) that lets you add new syntactical elements to the source files that AMC processes. In addition, AMC has a module structure reminescent of the UCSD p-System compiler. AMC comes with a default package that adds a dynamic form of OOP to C.
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.
APRIL is a symbolic programming language that is designed for writing mobile, distributed and agent-based systems especially in an Internet environment. It has advanced features such as a macro sub-language, asynchronous message sending and receiving, code mobility, pattern matching, higher-order functions and strong typing. The language is compiled to byte-code which is then interpreted by the APRIL runtime-engine. APRIL now requires the InterAgent Communications Model (ICM) to be installed before it can be installed.
ActivePerl is the industry-standard Perl distribution, available for Windows, Linux, Mac OS X, Solaris, AIX, and HP-UX. Complete and ready-to-install, the ActivePerl distribution includes core Perl, popular modules, the Perl Package Manager (PPM), and complete documentation. The Windows version provides additional features that have made ActivePerl the worldwide standard for Perl on Windows.
ActivePython is the industry-standard Python distribution, available for Windows, Linux, Mac OS X, Solaris, AIX, and HP-UX. It is 100% compatible with the reference distribution of Python. Code tested with ActivePython will run on any Python installation that has the appropriate extensions installed.
Alana is a highly responsive Turing Machine simulator with many examples, like (unary and binary) addition, subtraction and multiplication, "copy band content", string parsing examples, and divisibility and primality testing. The documentation contains an introduction to Turing Machines as well as some interesting theoretical information (halting problem, busy beaver, universal Turing Machines) and pointers to further literature.