CLI Collaborative Editing Research
===================================

The problem: Zed/VSCode have great collab features. What about terminal folks
who want to use vim/emacs/whatever but still pair/mob program in real-time?


HOW THE BIG PLAYERS DO IT
-------------------------

See detailed breakdowns:
  - vscode-liveshare.txt  (host-guest model, SSH relay, no CRDT)
  - zed-collab.txt        (true CRDT, anchors, tombstones, SumTree)

Quick comparison:

  VSCode Live Share:
    - Host-guest model (not true P2P)
    - All content stays on host machine
    - SSH tunnel (P2P or via Microsoft relay)
    - No conflict resolution needed - only one source of truth
    - Simpler but dependent on host connection

  Zed:
    - True CRDT - every replica is equal
    - Anchors instead of offsets (insertion_id + offset)
    - Tombstone deletions with version vectors
    - Lamport timestamps for ordering concurrent edits
    - Per-user undo via undo map
    - SumTree (copy-on-write B+ tree) everywhere

Key insight:
  VSCode = "remote desktop for code"
  Zed = "Google Docs for code"

For CLI collab, the Zed approach is more interesting because it's
truly decentralized and doesn't require a persistent host.


NEOVIM-SPECIFIC
---------------

instant.nvim
  https://github.com/jbyuki/instant.nvim
  - Pure Lua, no dependencies, CRDT-based
  - Run a server, others connect, real-time sync
  - Virtual cursors show where others are editing
  - Can share single buffer or entire session
  - Built-in localhost server, default port 8080
  - Commands: :InstantStartSingle, :InstantJoinSingle, :InstantStartSession
  - Separate undo/redo per user
  - This is probably the closest to Zed collab for terminal users

live-share.nvim
  https://github.com/azratul/live-share.nvim
  https://dev.to/azratul/live-sharenvim-real-time-collaboration-for-neovim-1kn2
  - Builds on instant.nvim with nicer UX
  - Still actively developed


TERMINAL SHARING (any editor)
-----------------------------

Upterm
  https://github.com/owenthereal/upterm
  https://upterm.dev
  - Modern tmate alternative, written in Go
  - NOT a tmux fork so you keep your tmux config
  - GitHub/GitLab/SourceHut/Codeberg auth
  - Community server: uptermd.upterm.dev
  - Supports scp/sftp file transfer
  - WebSocket fallback when SSH blocked
  - Can integrate with GitHub Actions for SSH debugging

tmate
  https://tmate.io
  - Fork of tmux 2.x, shares terminal sessions
  - Simple but stuck on old tmux, config conflicts

bottlerocketlabs/pair
  https://github.com/bottlerocketlabs/pair
  - Wrapper around tmux for quick pairing
  - Good for vim/emacs users


CRDT LIBRARIES (build your own)
-------------------------------

Cola (Rust)
  https://github.com/nomad/cola
  - Text CRDT for real-time collaborative editing
  - Peer-to-peer, no central server required
  - Could theoretically power an editor-agnostic collab layer
  - See: cola.txt in this dir for deep dive

Automerge
  https://automerge.org
  - More general CRDT library
  - Has bindings for many languages


THE MISSING PIECE
-----------------

Nobody has built the "any editor" dream yet. Would need:
  1. Shared CRDT document layer (cola/automerge)
  2. LSP forwarding to share language intelligence
  3. Thin clients for each editor connecting to shared state

This could be a fun project to explore.


QUICK START
-----------

To try instant.nvim:
  1. Install the plugin
  2. One person runs :InstantStartServer 0.0.0.0 8080
  3. Same person runs :InstantStartSession [ip] 8080
  4. Others run :InstantJoinSession [ip] 8080

To try Upterm:
  1. brew install owenthereal/upterm/upterm (or build from source)
  2. upterm host -- tmux new -s shared
  3. Share the SSH connection string with your pair