Nex

A practical, expression-oriented language with clean control flow, contracts, classes, and REPL-friendly ergonomics — designed to teach good software engineering practice: problem decomposition, interface design, invariants, and testable program structure.

Install Nex Nex in 15 Minutes

Highlights

Simple Core Clear syntax for values, functions, and control structures with minimal ceremony.

Engineering Discipline Contracts, decomposition, and clear interfaces so learners build correct software habits early.

Object + Functional Classes and methods alongside first-class functions and composable expression forms.

-- From Nex in 15 Minutes
function greet(name: String)
do
  print("Hello, " + name)
end

greet("world")

New to Nex? Take the fast tour in Nex in 15 Minutes, or learn it in depth with the book Programming with Nex. Then install the CLI and work through examples locally. Keep the Syntax Postcards and the complete class reference handy.

Install

Quick install

Download the bootstrap installer and run it. This installs the nex command so you can use it from anywhere.

bash <(curl -fsSL https://raw.githubusercontent.com/vijaymathew/nex/main/bootstrap-install.sh) jvm --install-deps

Recommended for full language support — REPL, formatting, documentation, and compilation tools.

Install without sudo

If you prefer a user-local install, place Nex under ~/.local and add the bin directory to your shell path.

bash <(curl -fsSL https://raw.githubusercontent.com/vijaymathew/nex/main/bootstrap-install.sh) jvm --prefix "$HOME/.local" && export PATH="$HOME/.local/bin:$PATH"

After installation, verify with nex help or start the REPL with nex.

Books

Programming with Nex A detailed introduction to the language — from fundamentals to larger programs, with clear examples and steady progression.
Beyond Code A software engineering book using Nex to teach decomposition, interface design, invariants, and the discipline required to build systems that stay understandable as they grow.
Tight Core, Open Edge Designing software that's both correct and flexible — constrain the core, open the edges, and let contracts be the membrane between them. A work in progress.
Contracts at Work Nine complete, runnable Nex projects — CLI tools, libraries, concurrent code, networked services, and a desktop GUI — with contracts holding each one together.
The Definition of Nex A formal account of the language — a precise description of both the grammar and the meaning of Nex, intended as the foundation for its implementation and use.
The Design and Implementation of Nex An implementation manual covering the parser, AST, interpreter, typechecker, code generators, library model, host integration, and concurrency runtime.