SlaveCode LogoSlaveCode.
Academy
RoadmapProblemsSystem Design
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
SlaveCode LogoSlaveCode.

Standardize your coding journey. From basic academy courses and guided roadmaps to advanced system design, company interview prep, and real-time coding arenas. The all-in-one platform to master algorithms and prove your engineering excellence.

Learn & Practice

  • Academy
  • Problems
  • Roadmap
  • System Design

Compete & Tools

  • Arena
  • Contests
  • Compilers

Legal & Support

  • Report an Issue
  • Privacy Policy
  • Terms of Service
  • Contact Us

© 2026 SlaveCode. All rights reserved.

Red

Red

Red is a next-generation full stack programming language, strongly inspired by REBOL.

Master Red with
Interactive Learning

Elevate your Red skills through 49 curated exercises across 0 core concepts. Master problem-solving with a structured learning path designed for modern developers.

Red

About Red

Red's characteristics mostly come from the fact that the basis of its creation was Rebol, and Red's development started as an open source community alternative. In the meantime, Rebol's development has stopped, and Red is constantly evolving.

Rebol legacy

Just like Rebol, Red is a general purpose programming language. You can use it to create any application you want. To be as familiar to developers as possible, multiple paradigms are implemented: imperative, functional, object, symbolic, and reactive. Although its entire toolchain fits in a 1.5 MB download, it has Graphical User Interface implementations for all major operating systems (Windows, Linux, macOS) and no dependencies on external libraries.

Red strives to be as simple as possible. It's designed by making the most usable compromises and choosing sensible defaults to allow the completion of every task without being overwhelmed by a number of choices. It's focused on human readability, so syntax sugar is reduced to a minimum and programs try to resemble sentences of natural language. As a result, Red and Rebol are highly expressive.

An unusual value of Red is its homoiconicity, so a Red program can be manipulated just like any Red data structure. Hence, Red and Rebol are also data formats. A fun fact is that JSON was inspired by Rebol.

Red

Compared to Rebol, Red has been greatly improved. It can be compiled to a single executable for every supported platform, using any of them. So, you can compile Windows programs on Linux or macOS programs on Windows. There is also a REPL console available, both command line and graphical, which enables instant manipulation of data with Red commands by typing them one-by-one.

What also differentiates Red is its dialect, Red/System, which makes Red a full stack language, allowing development of low-level code like in C.

Mission

  • Bring fun back into programming
  • Fight software complexity

Development

Red is open source. Its development is hosted in GitHub repository. Currently the project is in alpha stage, so expect things to change and break.

Key Features of Red

Full-stack

Red can be used to create a device driver as well as a GUI application.

Lightweight

Entire toolchain is about 1.5 MB download, single executable. Low memory footprint.

Code is data

Red is its own meta-language and own data-format. Program can operate on it's own code.

DSL

It's easy to create Domain Specific Languages, dialects and parsers.

GUI

It's simple as: view [b: base 100x100 button {Draw circle} [b/draw: [pen red circle 50x50 50]]]

Reactive

Objects can be linked by reactions to reduce size and complexity of program.

Track icon

Full-stack

Red can be used to create a device driver as well as a GUI application.

Lightweight

Entire toolchain is about 1.5 MB download, single executable. Low memory footprint.

Code is data

Red is its own meta-language and own data-format. Program can operate on it's own code.

DSL

It's easy to create Domain Specific Languages, dialects and parsers.

GUI

It's simple as: view [b: base 100x100 button {Draw circle} [b/draw: [pen red circle 50x50 50]]]

Reactive

Objects can be linked by reactions to reduce size and complexity of program.

Dive into Red practice challenges

Allergies
Allergies
Level 2

Given a person's allergy score, determine whether or not they're allergic to a given item, and their full list of allergies.

Anagram
Anagram
Level 2

Given a word and a list of possible anagrams, select the correct sublist.

Armstrong Numbers
Armstrong Numbers
Level 2

Determine if a number is an Armstrong number.

Atbash Cipher
Atbash Cipher
Level 2

Create an implementation of the atbash cipher, an ancient encryption system created in the Middle East.

Binary Search
Binary Search
Level 3

Implement a binary search algorithm.

Bob
Bob
Level 2

Bob is a lackadaisical teenager. In conversation, his responses are very limited.