cartularium

cartularium

A community of spreadsheet practitioners building everything we wished existed.

est. 2026 · 2 volumes · 1 instrument · open contributions

community discord ↗
in encyclopaedia 527 function pages →
in catalogue 251 divergences →
source github ↗
i.

The volumes

two published · one in development · one instrument
volume i · encyclopaedia sheets.wiki
sheets.wiki

An encyclopaedia of spreadsheet practice. Function reference, concept guides, blog.

functions concepts blog
function pages527 concept pages posts last edit2026-04-27
volume ii · catalogue assay.sheets.wiki
assay

A reference of where spreadsheet engines diverge. 251 divergences across eight engines, indexed by cause, with the fixture tests behind every claim.

gsheets excel lattice ironcalc hyperformula libreoffice formulas pycel
divergences251 engines8 causes last seeded
volume iii · registry + tool formulary.dev
formulary

A package manager and registry for named functions and lambdas: versioned, dependency-tracked, importable.

gsheets excel lattice named functions
statusin development packages functions first releasetbd
instrument · standalone latlang.org
lattice

A programming language with spreadsheet semantics: reactive cells, broad compatibility with other engines, and a compiled runtime.

engine ide language
statusin development version stdlib fns last build
ii.

What cartularium is

a community, with volumes

A community of spreadsheet practitioners collecting what we know into volumes anyone can cite.

Cartularium started as sheets.wiki: a durable place for the answers people kept retyping in Discord and Reddit threads, with a permalink and an edit history. The wiki kept running into questions it couldn't really answer on its own, mostly about how the engines disagree and whether somebody had already written the formula. Those gaps grew into the other volumes.

The name fits the shape. A cartularium in medieval Latin meant either a book of transcribed documents or the people who kept the book. Cartularium the imprint is both: the community writes down what it knows, and the community keeps the record current.

iii.

Recent across the imprint

newest first
2026-04-27 cartularium The volumes now share a top bar, mobile drawer, table of contents, and footer line. Move between the wiki and the catalogue and the chrome reads the same. repo →
2026-04-26 sheets.wiki Footnotes on long blog posts now float into the page gutter beside their paragraph instead of bouncing the reader to the foot of the page. blog →
2026-04-22 sheets.wiki /functions indexes every documented function on a single page. 527 entries across 19 categories, exported as html, tsv, and json for anyone who wants the data outside the wiki. /functions →