Why can't you diff or review changes to a PowerPoint file?

A .pptx is a zip of XML, binaries, and a manifest. Editing one cell makes the binary diff span hundreds of lines of unrelated metadata, so side-by-side change review is impractical. Plain avoids this by keeping every deck, doc, and dashboard as plain text source (Markdown or Plain DSL with YAML frontmatter), so edits show as clean line-level diffs.

How does Plain make documents version-controllable like code?

Plain stores every artifact as text source, not a binary file. Editing a slide title changes one line; reordering sections changes a few position hashes; switching theme changes a single token. This yields real diff history, precise rollback, and inline human review with green additions and red removals, like a code review on a deck or doc.

How do AI edits and multiple editors work without merge conflicts in Plain?

AI edits land as one-line replacements in JSON Patch (RFC 6902) notation, making them cheap, exact, and version-tracked. For concurrent human editing, Plain uses Yjs CRDTs to merge text edits cleanly, so two people editing different slides never hit a merge-conflict dialog.

Can a legal or compliance team review a Plain deck before it ships?

Yes. Because the deck is a text file in a Plain workspace, a reviewer can open a review request and see exactly what changed since their last approval, comment inline, and have the thread track which version each comment was addressed in. It is standard code-review infrastructure applied to documents.

Is Plain open source since its documents are diffable text?

No. Plain's product is closed-source, but its document source is open, portable text (Markdown and Plain DSL), so the diffing benefits do not depend on the codebase being public. You can clone a Plain workspace and edit the same text in your own editor. Plain offers Free, Pro $20, Max $100, and Team $25/seat tiers.

2026-05-264 min·#engineering#thesis

Diffable documents: why every artifact in Plain is git-ready

Zephyr WhimsyEditorial · 2026-05-26

What happens when documents become version-controllable like code.

Reviewing changes to a binary file is impossible. Reviewing changes to text is routine. We've known this in software engineering for forty years. We haven't applied it to documents.

Plain's source is text. Every deck, every doc, every dashboard starts life as Markdown or Plain DSL with YAML frontmatter. When you edit a slide title, what changes in the source is one line. When you reorder sections, what changes is a few hashes of position. When you switch theme, what changes is a single token.

What this enables

Real version history. Not "v3_final_REAL.pptx" on your desktop. Actual diff history where you can see what changed and roll back precisely.
Review by humans. Your colleague can see your changes the way they'd see a code review — additions in green, removals in red, conversation in margins.
AI can edit specific things. "Change the third paragraph" lands as a one-line replace in JSON Patch notation. Cheap, exact, version-tracked.
Concurrent editing. Yjs CRDTs merge text edits cleanly across collaborators. Two people editing different slides doesn't produce a "merge conflict" dialog.

The Office file world doesn't have this

A .pptx is a zip of XML plus binaries plus a manifest. Opening two versions side by side and seeing what changed is, in practice, impossible. Modify one cell, and the binary diff spans a hundred lines of unrelated metadata. So nobody reviews document changes the way they review code changes.

Plain unconditionally produces text as source. The same Plain DSL works whether AI is generating it, you're editing it in the workspace, or you're cloning the repo and editing it in your editor of choice.

Practical example

At some companies, board decks need approval from the legal team before they go out. Today that's "send the .pptx, hope they catch issues by reviewing every slide visually."

With Plain: the deck is a text file in a Plain workspace. Legal opens a "review request," sees exactly what changed since their last approval. They comment inline. The author addresses comments — and the comment thread tracks which version was addressed.

That's not exotic technology. That's just code-review infrastructure, finally applied to documents.

The long arc

We think every artifact your company produces — deck, doc, dashboard, training material, brand guide, investor update — deserves the same engineering rigor you give code. Versioned. Reviewable. Reproducible. AI-readable.

That's what "diffable" means. And that's why Plain's source is text.

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