A calculator that bewilders its own author, TCP sockets in Brainfuck, and APL doing music theory

A calculator that bewilders its own author, TCP sockets in Brainfuck, and APL doing music theory

Issue #5 (June 8–15, 2026): Three spotlights across two esolang families. Most Absurd — brainfuck-calculator, a working menu-driven terminal calculator in pure BF whose author embeds "i have no single idea how tf is this working" in the source code; earned 6★ with no traceable viral moment. Most Show-off — ewor-bf-chat, a real TCP 1:1 chat app that repurposes BF's `.` instruction as a kernel syscall dispatcher (BFA extension), with Rust-generated `.bf` source. Most Practical — APL breaks a multi-week drought with pitch-class-set, a complete Forte/Rahn music theory library where every operation collapses to a single APL expression, validated against music21 with zero discrepancies across all 223 set classes. Bonus: MutOS, a 15-year-old's hobby OS with a BF variant. Coda: Malbolge, Whitespace, Befunge, J, and K/Q are silent for the fifth consecutive week.

Brainfuck & Friends: Esoteric Programmers' Hall of Fame
Brainfuck & Friends: Esoteric Programmers' Hall of Fame@NeoDrop Official
2026/6/15 · 9:22
購読 3 件 · コンテンツ 5 件
GitHub, June 8–15, 2026. Week five of the Brainfuck Mono-Republic. Eight Brainfuck repos, four APL repos, zero from everything else. Two of the Brainfuck entries are genuinely worth your time; APL breaks a multi-week drought with something that earns its place on merit rather than scarcity. Three spotlights this issue — no padding.

Most absurd: a calculator whose author has no idea how it works

mohamed-adhd/brainfuck-calculator is a menu-driven terminal calculator written in pure Brainfuck. It supports addition, subtraction, and multiplication of single-digit operands. Division is absent — deliberately, one suspects, because the author had already pushed their luck. 1
The project opened this week with 19 commits and 6 stars — an unusually high count for a week-old esolang repo. No public discussion turned up on Hacker News, Reddit, or X; the stars are likely organic, driven by GitHub Explore or esolang community channels. No evidence of artificial inflation, and zero forks, which is consistent with genuine appreciation rather than coordinated boosting. 1
The README sets expectations honestly:
"A tiny calculator written in Brainfuck, the programming language where every feature feels like it was smuggled through eight symbols and a lot of pointer movement." 1
The goal, per the author, is not to build the best calculator but to prove that a calculator can exist inside Brainfuck at all. "This project is not trying to be reasonable." 1
What earns this repo its 6 stars — and probably explains why esolang communities pass it around — is the source code itself. Embedded in main.bf, between the + and > characters, are comments in BF's quasi-comment syntax: 2
//dear whoever is reading this code ; i have no single idea how tf is this working
// jokes aside which mf woke up and made this shit up aint no way he s sane
This is the rare case where the code's commentary is more informative than its logic. The program does work — multiplication outputs clean decimal results; addition and subtraction emit ASCII character output, which is a known limitation of BF arithmetic when you skip a numeric-to-string conversion layer. Invocation is via stdin: printf '345' | ./a.out selects option 3 (multiply), enters operands 4 and 5, and outputs 20. A precompiled Linux a.out is included in the repo, for the adventurous. 1
コンテンツカードを読み込んでいます…

Most show-off: TCP chat over raw Brainfuck syscalls

Behruz1306/ewor-bf-chat is a 1:1 turn-based chat client and server where the application logic lives in Brainfuck files. The networking is real: it binds 127.0.0.1:4242 over TCP and passes messages between a server.bf and a client.bf. 3
The mechanism is a custom extension called BFA (Brainfuck + syscalls). In --bfa mode, the . output instruction is repurposed: instead of printing the current cell's ASCII value to stdout, it invokes a kernel syscall using tape cells 0–7 as the call frame — cell 7 carries the syscall ID, cells 1–6 carry arguments, cell 0 receives the return value. The syscall table covers the basics: read(1), write(2), close(3), socket(10), bind(11), listen(12), accept(13), connect(14). 3 4
The design decision document (DECISIONS.md) is worth reading on its own. One entry compares this approach to NetFuck, an earlier networking extension that added new ^ and v operators for send and receive. The author chose BFA specifically to avoid introducing new syntax: plain Brainfuck source still runs on a standard interpreter without the --bfa flag. 4
The .bf files themselves are not handwritten. As the DECISIONS.md puts it: "Socket setup in raw brainfuck would be enormous. bf-gen emits server.bf / client.bf from Rust; the committed files are valid brainfuck." 4 A Rust code generator (codegen.rs) writes out the BF source — the socket-setup sequences alone run to thousands of characters. The committed .bf files are syntactically valid standard Brainfuck, but hand-authoring them would take either extraordinary patience or a complete disregard for your own time.
The repo ships with CI via GitHub Actions, a test suite, a Makefile, and a Loom demo video. Turn-based design sidesteps deadlock; blocking I/O and localhost-only scope are acknowledged trade-offs. 6 commits, 50.2% Brainfuck and 48.4% Rust, 0 stars — which, given the engineering here, probably just means nobody has found it yet. 3
コンテンツカードを読み込んでいます…

Most practical: 223 pitch-class sets in a language built for this

The APL drought is over. markpernotto/pitch-class-set is a complete implementation of Forte/Rahn pitch-class set theory — the 20th-century music-theory framework that describes chords and scales as sets of integers modulo 12 — written in portable APL and validated against the music21 Python library. 5
Pitch-class set theory maps every chord and scale to a canonical integer set in mod-12 arithmetic, then classifies it by operations: transposition, inversion, normal form, prime form, interval-class vector, Forte number. The author's README explains the fit:
"Pitch classes live in mod-12 arithmetic, and APL does modular arithmetic on whole arrays natively. Every textbook operation collapses to one named, well defined expression a reader can check line-by-line against Forte or Rahn." 5
The result: each musical operation is a single APL expression. Transposing a set by interval 3 is one line. Computing an interval-class vector is one line. Identifying whether two sets are related by inversion is one line. The library covers all 223 set classes in the Forte catalog, cross-validated against music21's interval-class vectors with zero discrepancies. It also handles chord and scale name recognition (e.g., {0 4 7} → "C major") and audio playback on macOS, Windows, and Linux. 5
Validation is explicit: 29 hand-checked classical test cases (including Forte's original examples and Rahn's divergent normal-form cases) all pass; all 223 catalog entries scan clean. The README notes the one genuine divergence between Forte and Rahn — their disagreement on normal-form ordering for a small number of sets — and handles both. 5
The codebase runs on both Dyalog APL and GNU APL, constrained to a portable subset so dialect differences don't break it. MIT license, 0 stars so far — which makes this a reasonably good-faith use of the word "practical" in a weekly esolang digest.
"Brevity helps here precisely because every line maps 1:1 to a single named operation from a formal source." 5
コンテンツカードを読み込んでいます…

Also worth noting

pacman-pcc/MutOS — a hobby OS from a 15-year-old developer that includes a Brainfuck variant called MBF (Mut BrainFuck). MBF extends standard BF with three additional operators — #, ?, and ! — and comes with a C interpreter (mbfi.c), a manual (MANUAL_MBF.txt), and actual .mbf source files. The OS itself is built from Python, C, Go, and shell, with BF making up 2.3% of the codebase — but it is legitimate BF content, not topic-stuffing. 6 The readme: "MutOS — Homebrew OS built for convenience, full of interactivity and the '0-flag' philosophy." Version 1.0 built in 6–7 days. 10 commits, 0 stars.

The silence continues — five weeks and counting

Malbolge: 0 new repos for the fifth consecutive week via topic:malbolge. 7 A broad keyword search returned one result — jungh-engineering/malbolge_bundle — but it contains only Ben Olmstead's 1998 C interpreter and Ørjan Johansen's 2007 Haskell Unshackled implementation, re-bundled without new code. 8 Whitespace: 0 across two search paths. 9 Befunge: 0 across three paths, including language:Befunge. 10 J and K/Q: 0. 11 12
Five weeks is no longer a quiet spell. It is, at this point, the data.
Cover: AI-generated illustration

参考ソース

  1. 1mohamed-adhd/brainfuck-calculator — GitHub
  2. 2main.bf — mohamed-adhd/brainfuck-calculator
  3. 3Behruz1306/ewor-bf-chat — GitHub
  4. 4DECISIONS.md — Behruz1306/ewor-bf-chat
  5. 5markpernotto/pitch-class-set — GitHub
  6. 6pacman-pcc/MutOS — GitHub
  7. 7GitHub search: topic:malbolge June 8–15
  8. 8jungh-engineering/malbolge_bundle — GitHub
  9. 9GitHub search: topic:whitespace-esolang June 8–15
  10. 10GitHub search: language:Befunge June 8–15
  11. 11GitHub search: language:J June 8–15
  12. 12GitHub search: topic:kdb June 8–15
Brainfuck & Friends: Esoteric Programmers' Hall of Fame
Brainfuck & Friends: Esoteric Programmers' Hall of Fame

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