Hi, I'm Fred. I build software.

I'm interested in programming languages, philosophy, hypertext systems, and how smaller and simpler approaches to programming can turn computers into creative tools for thought. Here's what I'm currently working on:

• Kombucha — a malleable programming language
• terminator — programming with paradoxical loop values
• Slayerfest — simulating academia by writing Buffy papers

Reach out at kettelhoit@gmail.com

Notes | Projects

Notes

I write weekly lab notes about my experiments:

November 2025

• Hypertext: hubs instead of bridges
• Hypertext: space without center and margin

October 2025

• RC week 24: Recurse Center return statement
• RC week 23: Slayerfest — in every generation there is a conference
• RC week 22: paradoxical values as unordered time loop maps
• RC week 21: a programming language as a series of experiments
• RC week 20: high contrast, it's cool

September 2025

• RC week 19: a sketch for a time loop calculus, part 2
• RC week 18: a sketch for a time loop calculus
• RC week 17: test cases for paradoxical fixed points
• RC week 16: the halting problem, time loops and paradoxes

August 2025

• RC week 15: Kombucha's fundamental data types
• RC week 14: layered programming, symbiotic programming
• RC week 13: reasonable macros through explicit bindings, part 3
• RC week 12: tail call statement (Recurse Center in numbers)
• RC week 11: reasonable macros through explicit bindings, part 2

July 2025

• RC week 10: reasonable macros through explicit bindings
• RC week 9: live reload with replay semantics
• RC week 8: an efficient VM for a functional language
• RC Week 7: introduction to live reloading with replay semantics

June 2025

• RC Week 6: a game of life for language evolution?
• RC Week 5: hot reload with replay semantics?
• RC Week 4: building a language to write a blog post
• RC Week 3: A Gentle Introduction to Vorpal
• RC Week 2: Pattern Matching, VM Instruction Set

May 2025

• RC Week 1: Vorpal—A Minimal and Malleable Language
• 12 Weeks of Writing Weekly Lab Notes
• Throw Away the Compiler, But Keep the Tests
• A Stack-Based Bytecode VM for Vorpal

April 2025

• One Must Imagine Sisyphus Happy: Throwing Away All Code, Every Day
• Reasonable Macros (From Fexprs to Explicit Bindings)
• What Makes a Programming Language Powerful?
• Minimal Modern Syntax (Without (All (the ())))

March 2025

• Custom Binding Constructs Without Macros, Part 3: Generalizable Sugar
• Custom Binding Constructs Without Macros, Part 2: Desugaring Bindings
• Custom Binding Constructs Without Macros, Part 1: Explicit Bindings
• A Static Site Generator in Lambda Calculus With Effect Handlers
• Turning Lambda Calculus Into a Minimal Programming Language

Projects

• statically-typed language, Garble, that compiles to boolean circuits.
• PostScript quine that draws itself as a random maze whenever it's printed.
• hypertext system that is both a document and graph DB, written in Rust.
• md/pdf/epub pipeline and generative cover art for Wittgenstein ebooks.
• visualization of connections in Wittgenstein's philosophical Nachlass.
• PhD dissertation on Wittgenstein, diagonalization, Cantor, Gödel and Turing.