Features

Array oriented

Designed for processing of multidimensional arrays with a wide variety of data types and numerical precisions available, allowing the application of operations to an entire set of values at once without needing explicit loops.

Concise

Terse notation that was designed by Kenneth Iverson as a perfected form of the APL language, for which he won the Turing Award. The brevity of the syntax allows for expressive code that can perform complex operations with minimal lines of code.

Fast

Highly optimised, efficient interpreter written in C. Makes use of vectorization by using relevant SIMD depending on target architecture.

Point-free (tacit)

Function-level programming via point-free tacit programming. Functions can be defined without explicitly referring to their arguments using features such as hooks and forks which are practical applications of combinator calculus.

Small footprint

The binary file of J interpreter (as CLI or DLL) requires only 5MB of memory.

Multi-threading

Primitives for parallel program execution and threads synchronization to make your programs even faster.

Object Oriented

Flexible hierarchical namespace scheme (where every name exists in a specific locale) can be effectively used as a framework for both class-based and prototype-based object-oriented programming.

Unique debugging tools

Built-in tool that visualizes the execution of J sentences by displaying their step-by-step breakdown. It generates an interactive graph showing intermediate results and errors.

Cross platform

Available for various operating systems: Windows, Linux, macOS, Android. Available also in your browser and as a cloud service.

Extensive knowledge base

On-line library of books, journals, essays and community forum.

Educational lab system

Number of educational code notebooks allowing interactive training of various aspects of J language from beginner to advanced.

Multiple add-ons

Extensions of the language for data manipulation including high-performance columnar RDBMS, computation, maths, statistics and more.