Value]] Sum: [Product any [["+"| "-"] Product]] Expr: Sum parse/all "12+13" Expr Implementations The official Rebol 2.7.8 implementation is available in several editions (/Core, /View, /Command, /SDK and /IOS). Both /Core and /View editions are freely redistributable software. The runtime environment is stored in a single executable file. Rebol/Core 2.7.8, the console edition, is about 300 KB and Rebol/View 2.7.8, the graphical user interface edition, is about 650 KB in size. Rebol/View provides platform-independent graphics and sound access, and comes with its own windowing toolkit and extensible set of styles (GUI widgets). Extended editions, such as Rebol/Command 2.7.8 or Rebol/SDK 2.7.8 require a paid license; they add features like ODBC data access, and the option to create standalone executable files. Legacy Rebol was named by Douglas Crockford as one of the inspirations of JavaScript Object Notation. Rebol inspired the open-source Orca project, which is an interpreted Rebol-like language. Boron is an interpreted, homoiconic language inspired by and similar to Rebol, which is meant for embedding domain specific languages. It is implemented as a C library licensed under the terms of the LGPLv3. The Red programming language was directly inspired by Rebol, yet the implementation choices of Red were geared specifically to overcoming its perceived limitations. See also Domain-specific language Language-oriented programming References Further reading External links A REBOL tutorial Rebol 3 Tutorial Programming languages AmigaOS 4 software Dynamic programming languages Dynamically typed programming languages Functional languages Prototype-based programming languages Scripting languages Extensible syntax programming languages Formerly proprietary software Programming languages created in 1997 High-level programming languages Homoiconic programming languages