The Queen Mum of Weblog Hosting Systems – written in server-side JavaScript since 2001.

Helma web framework

An interpreter for the Piet programming language

Visual Studio Code extension providing support for syntax coloring of Helma skins etc.

an interpreter for the programming language piet written in haskell

Standard Interpreter for Malbolge, ported from Ben Olstead's original C interpreter.

Funge-98 interpreter and debugger written in Haskell

An implementation of the Malbolge interpreter in Rust.

Haskell Unlambda Interpreter

Curated list of awesome Esoteric languages and resources

Albus is a Whitespace interpreter written in Rust.

A simple Whitespace VM written in Rust

Whitespace interpreter

The Fungus virtual machine

Yet Anonher Brainfuck Interpreter

Ruby, Python, and Haskell interpreters for the Piet language

The canonical Whitespace interpreter written in Haskell, modified for modern compilers

Small brainfuck interpreter written in Rust.