While sampling 100 different programming languages, I compiled a list of intriguing programming languages. Although I tested out a lot of languages, there are still many I never got around to--not because I didn't think they were promising--sometimes they just didn't match what I wanted at the time or they were too similar to other languages I'd recently used.

If you're looking for inspiration for your own programming language experiments, consider these! I have bolded the ones I personally was most interested in.

Object-oriented

• Pharo: being a Smalltalk, it includes an entire IDE
• Squirrel: object-oriented scripting language for games
• Crystal: Ruby-like compiled language
• io: minimal, pure object-oriented language

Functional

• Logo: educational language from the 60s, with turtle graphics
• Elixir: Erlang-compatible functional language
• Koka: functional language with effect types and handlers
• Scrapscript: sounds kind of like Unison on IPFS?
• Gren: compiles to JavaScript
• EYG: provides a structural editor

Lisp

• newLISP: reimagined, batteries-included Lisp
• Emacs Lisp: (probably) the world's most popular Lisp (note: not purely functional, as far as I understand)
• Basilisp: Clojure-inspired Lisp that targets Python
• jank: Clojure-inspired language that is compiled via LLVM
• Otus Lisp: very small Scheme implementation
• Coalton: statically-typed Lisp

Logic programming

• Curry: functional logic programming language

Assembly

• CHIP-8: the world's oldest fantasy console?

Imperative (compiled)

• Oberon-2: Pascal-like, possibly with a single-pass compiler?
• Red: systems-level, but inspired by Rebol
• Vale: memory-safe language that is simpler than Rust (but currently incomplete) -- I really wanted to try this one, but I think the compiler required Java and I didn't have a working Java setup at the time
• Borgo: built on Go, but with a more expressive language
• Mojo: Python, but compiled -- note: closed source, as far as I can tell
• Scopes: another "better C"? -- note: I consider this to be a good thing!
• D: C++-alternative with an optional garbage collector (and tons of other features)
• MUMPS: "Massachusetts General Hospital Utility Multi-Programming System" from the 60s
• bl: "simple programming language created for fun"
• Jakt: programming language developed as part of the SerenityOS project
• SectorC: a partial C compiler that (somehow) fits in a 512-byte boot sector
• Beef: created for game development, includes a full (Windows-only) IDE
• PL/0: educational programming language by the creator of Pascal
• FreePascal: modern day Pascal that supports many targets

Imperative (interpreted)

• PILOT: imperative language from the 60s
• Antimony: aims to be simple
• Elvish: modern shell scripting language
• Amber: compiles to Bash
• MiniScript: a small, new, embeddable scripting language (think: a modern Lua)

Concatenative

• Joy: purely functional, but supposedly similar to Forth
• SectorForth: Forth implementation that bootstraps from a 512-byte boot sector
• nf: minimal interactive programming language

Data-driven

• Streem: prototype stream-based programming language