hex

hex is a tiny, minimalist, slightly-esoteric programming language implemented in C that can be used to learn about concatenative programming and create shell scripts.

Its syntax borrows heavily from the min programming language, and it is stack-based, but it only supports:

• 32bit integers written only in hexadecimal format
• strings
• quotations (lists)
• symbols

It comes with 0x40 (64) predefined native symbols to perform arithmetic operations, bitwise operations, comparisons, boolean logic, string and list manipulation, stack manipulation, I/O, file I/O and shell command execution.

It also lets you define your own symbols, but they will always be global (there is no lexical scoping or similar).

Despite its quirks, hex aims to bring more people into the world of concatenative programming. The language web site includes a short tutorial, a simple specification of the language, and even a WASM-powered playground with an actual hex REPL to play with.