Notion
A cloud-based all-in-one workspace (notes, docs, wikis, databases, kanban, tasks). Introduced to this wiki by notion-wikipedia as the commercial-mass-market counterpoint in the PKM landscape.
What it is (from the source)
- Block-based, but organized heavily around structured databases and real-time team collaboration — less link-centric than the zettelkasten/roam-research lineage.
- Proprietary and cloud-hosted: your data lives on Notion’s servers, not as local plain files — the opposite of logseq/obsidian/tiddlywiki5.
- The landscape’s commercial winner by a wide margin (20M+ users, $500M+ ARR).
- Adding agents: a Developer Platform with 1M+ “Custom Agents” (since Feb 2026) — a mild bridge to cluster B’s agent products.
The contrast it sharpens
Notion is the test case for cluster A’s “convergence on networked notes as plain markdown you own” claim. It shows the convergence holds for the local-first / tools-for-thought crowd (the lineage the llm-wiki builds on) but not for the mass market, which traded ownership/portability and associative linking for convenience, collaboration, and structured databases. So “own your plain files” is a deliberate value choice, not an inevitability — which is part of why the LLM-wiki pattern picks plain markdown on purpose.
Related
notion-wikipedia · logseq · obsidian · roam-research · llm-wiki