# 260614 — Literate Programming (Knuth's WEB / weave / tangle) deep dive

Date: 2026-06-14 · Source: **SHARD-WP-0004 T1**

## What this is

A deep dive into **literate programming** — Knuth's WEB and the **`weave`/`tangle`** model
— as the deepest ancestor of shard-wiki's **projection** and **transclusion** ideas
applied to *executable* content. The keystone: **one canonical source → two co-derived
projections** (typeset docs via `weave`, compilable code via `tangle`), plus **named code
chunks** assembled by reference (transclusion).

## Why it matters

- Establishes **one-source-many-projections** as a page-model + projection pattern that
  *generalizes* compile-to-static (UC-79, single output) to **N co-equal, semantically
  different** derived views — feeds SHARD-WP-0002 **T12/T16**.
- Splits projection into **replication-projection** (lazy cache, current default) vs
  **derivation-projection** (transform/compile/weave/evaluate) — a distinction the rest of
  the computational batch (notebooks, REPLs) extends.
- Named chunks are the **executable-content face of transclusion / compose-by-reference**
  (UC-32 / UC-44).

## Yield

- **UC-83** (new): attach a single-source-multiple-projection (literate) artifact; present
  each derived view with output→source provenance; edits target the source.
- Enrich **UC-32**, **UC-44**, **UC-79**; links **UC-54** (computed/evaluated projection,
  → T3 Jupyter).

## Contents

| Path | Role |
|------|------|
| `findings.md` | WEB model, named-chunk transclusion, descendants (noweb/org-babel/knitr/Jupytext), capability profile, INTENT mapping, UC seed, architecture notes, open questions |