shard-wiki/research/260613-twiki-deep-dive/README.md

# 260613 — TWiki deep dive (implementation, plugin API, ecosystem)

Date: 2026-06-13

## What this is

A focused study of **TWiki** — the original "structured enterprise wiki / wiki
application platform" (Peter Thoeny, ~1998), and the **file-based Perl counterpoint**
to XWiki's Java/DB platform. Covers TWiki's **implementation** (Perl + flat-file +
RCS store, Webs/Topics, TWiki Forms, TWikiML/variables), the **plugin API and
handler callbacks** that extend the core, the **extension package types** (Plugin /
Skin / AddOn / Contrib) and repository, and TWiki's **per-topic access control**
(the prior art behind yawex's `AccessControl`).

Read through shard-wiki's lens, paired with the XWiki dive: TWiki shows the same
"wiki-as-application-platform" goal reached with **text files + RCS** instead of a
database — which changes the adapter story (direct on-disk attach, git-convertible
history).

Complements:
- `research/260613-xwiki-deep-dive/` — the DB/Java app-platform sibling
- `research/260608-wikiengines-overview/` — the landscape scan
- `research/260608-yawex-prior-art/` — yawex borrowed TWiki's per-topic AccessControl

Note: most of TWiki's community forked to **Foswiki** in Oct 2008 (from TWiki
4.2.4); findings flag where TWiki/Foswiki differ.

## Contents

| Path | Role |
|------|------|
| `findings.md` | Architecture, plugin-handler API, ecosystem, capability profile, INTENT mapping, UC seeds, sources |

## Status

Initial deep dive complete. Two new use cases promoted to
`spec/UseCaseCatalog.md` (UC-40, UC-41); UC-06/34/36/38/39 enriched with TWiki
specifics. Adapter-contract implications feed
`workplans/SHARD-WP-0002-federation-architecture.md`.
research: TWiki deep dive (impl, plugin API, ecosystem); UC-40/41 Deep dive into TWiki as the file-based Perl counterpoint to XWiki: flat-file + RCS store (data/<Web>/<Topic>.txt), Webs/Topics, TWiki Forms storing fields as %META% in the topic text, TWikiML/variables, TWiki::Func API; the plugin handler callback surface (initPlugin, commonTagsHandler, before/afterSaveHandler, afterRenameHandler, REST handlers) and package types (Plugin/Skin/AddOn/Contrib); per-topic ALLOW/DENY access control (origin of yawex's model); Foswiki fork. Catalog (now 41 UCs): - UC-40 attach a file-backed engine's on-disk store directly (dual-path attach) - UC-41 import an engine's native file history (RCS .txt,v) into the journal - enrich UC-06 (TWiki per-topic ACL lineage), UC-34 (file-embedded %META%), UC-36 (RCS-import vs DB-supplement), UC-38 (TWiki handlers as adapter host) Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> 2026-06-13 23:20:11 +02:00			`# 260613 — TWiki deep dive (implementation, plugin API, ecosystem)`

			`Date: 2026-06-13`

			`## What this is`

			`A focused study of TWiki — the original "structured enterprise wiki / wiki`
			`application platform" (Peter Thoeny, ~1998), and the file-based Perl counterpoint`
			`to XWiki's Java/DB platform. Covers TWiki's implementation (Perl + flat-file +`
			`RCS store, Webs/Topics, TWiki Forms, TWikiML/variables), the **plugin API and`
			`handler callbacks that extend the core, the extension package types** (Plugin /`
			`Skin / AddOn / Contrib) and repository, and TWiki's per-topic access control`
			(the prior art behind yawex's `AccessControl`).

			`Read through shard-wiki's lens, paired with the XWiki dive: TWiki shows the same`
			`"wiki-as-application-platform" goal reached with text files + RCS instead of a`
			`database — which changes the adapter story (direct on-disk attach, git-convertible`
			`history).`

			`Complements:`
			- `research/260613-xwiki-deep-dive/` — the DB/Java app-platform sibling
			- `research/260608-wikiengines-overview/` — the landscape scan
			- `research/260608-yawex-prior-art/` — yawex borrowed TWiki's per-topic AccessControl

			`Note: most of TWiki's community forked to Foswiki in Oct 2008 (from TWiki`
			`4.2.4); findings flag where TWiki/Foswiki differ.`

			`## Contents`

			`\| Path \| Role \|`
			`\|------\|------\|`
			\| `findings.md` \| Architecture, plugin-handler API, ecosystem, capability profile, INTENT mapping, UC seeds, sources \|

			`## Status`

			`Initial deep dive complete. Two new use cases promoted to`
			`spec/UseCaseCatalog.md` (UC-40, UC-41); UC-06/34/36/38/39 enriched with TWiki
			`specifics. Adapter-contract implications feed`
			`workplans/SHARD-WP-0002-federation-architecture.md`.