What is XTXP?

XTXP (XML to XML Protocol) lets many people edit the same XML document at the same time, on different software, over unreliable networks. Anyone can session the document’s history, preview a session over the original, and merge it back.

The first document type is SVG, so the first application is a shared vector canvas with spatial chat and comments. It isn’t a separate layer: the canvas, chat and comments are views that muppet provides wherever it runs. The engine is not SVG-specific, though. Any XML tree works, and an HTML page parsed into a tree is close enough, which is what makes live web branching possible.

The problem

Collaborative design tools today mostly share three traits:

1. Identity and data live with one vendor. Your drawing and your account sit in that company’s cloud.
2. Collaboration needs their client. Usually that means a heavy JavaScript app, or a desktop app that only talks to its own servers.
3. History is linear. You can undo, but you can’t session, preview a session over the current state, and merge it back.

The XTXP answer

• Identity as a public key, fetched to a device through a sign-in people already have, so no central account owns anyone.
• A CRDT engine (Xmesh) that merges concurrent edits without a central authority. Every client runs it, so desktop clients keep working offline.
• Sessions as history. Going back to an earlier version, proposing an edit and previewing it are all the same thing: a session forked from a point in history. Ctrl+Z still undoes just your own recent actions.
• Plain HTML as a first-class client. A server-side muppet does the CRDT work for a browser that only submits forms and follows links.

Status

This is a design in progress. The decision log records what has been settled and the open questions list what hasn’t. No implementation code exists yet. The plan is to define behaviour first, as test vectors, and build after.