mmux vs Orca

What is Orca?

Orca is an open-source desktop app from Stably AI for running a fleet of coding agents in parallel. Its GitHub repository describes it as "the ADE for working with a fleet of parallel agents". You run Codex, Claude Code, OpenCode, Pi or any other CLI agent with your own subscription, each in its own git worktree, and track them in one place [2]. It is MIT-licensed and available for macOS, Windows and Linux, with a mobile companion app for iOS and Android [1] [2].

Around the agents it bundles an IDE: terminal splits with scrollback that survives restarts, a VS Code-style editor, an embedded Chromium browser whose Design Mode sends a clicked element's HTML, CSS and a screenshot to the agent, diff review with comments that go back to the agent, GitHub and Linear integration, usage tracking for Claude and Codex accounts, and an orca CLI that agents can use to drive the app [2]. Locally, a background daemon keeps agents running when you quit the app [5].

For remote work, SSH worktrees run agents on another machine: Orca sets up its own server on the host on first connect, reconnects after a drop and forwards ports [4]. Remote Orca Servers (beta) let one computer hold projects and agent sessions while a desktop or mobile client connects to it, typically over Tailscale [6].

Where Orca is better

• An editor and a browser next to the agents. Orca has a VS Code-style editor, drag-and-drop of files into a prompt, Markdown and PDF previews, and a per-worktree Chromium browser with Design Mode. mmux has none of that; it hands files to your $EDITOR and links to your browser.
• Review that talks back to the agent. In Orca you comment on diff lines and the comments go to the agent, and you can browse and review GitHub PRs and Linear issues in the app. The mmux git panel commits, pushes and merges, but has no PR or issue tracker view.
• Remote work from a local window. Orca's SSH worktrees give you editing, git and terminals on a remote host from your desktop, with automatic reconnect and port forwarding that scans the host for listening ports. With mmux you run it on the host and handle port forwarding with your own SSH setup.
• Fanning one task out. Orca can send one prompt to several agents, each in its own worktree, so you compare results and merge the best one. In mmux you start each worktree and agent yourself, or script it with mmux worktree new --prompt.
• Phones and Windows. Orca has native iOS and Android apps that notify you when an agent finishes, plus a native Windows build and Intel Mac support. mmux reaches a phone only through an SSH client, and has no native Windows or Intel Mac build.

Where mmux is better

• The whole environment lives on the server. mmux runs on the machine doing the work, inside a per-directory tmux session. Closing the terminal or dropping SSH detaches, and the agents keep running until you quit mmux there. There is no grace period to tune and no desktop app needed on the client: any terminal with SSH, including one on a phone, is enough.
• Dev servers as first-class processes. Processes such as a dev server are declared in mmux.yaml, started and stopped from the sidebar, and can define a stop: command that runs on quit. Only one checkout of a repository runs a given process at a time, so a worktree reuses the same ports and localhost:3000 is always the branch you last started it in.
• Worktrees that clean up after themselves. A new worktree gets your .env files copied across at every depth and an optional setup: command. M merges it back into the branch it came from, and a finished worktree (clean, idle, merged or pushed) is removed after 30 minutes by default.
• Session restore after a quit, crash or reboot. Reopening a directory brings back the agents and terminals you had open, and Claude, Codex, Pi and Grok agents resume their conversation. Orca restores layout and scrollback after a reboot, but you re-run the agent.
• Small footprint. mmux is one Rust binary plus tmux. It keeps itself up to date when installed with the script, and you configure it with two YAML files you can check into a repository.
• Notifications over SSH. mmux raises desktop notifications through terminal escape sequences, so an agent that finishes on a remote host pops up on the machine your terminal runs on.

When to use which

Using Orca and mmux together

mmux is a terminal program, so it runs in any terminal, including an Orca terminal pane on a local or SSH worktree. One way to split the work:

1. On the server, start mmux in the project. Agents and dev servers live in its tmux session from now on.
2. Connect Orca to the same host as an SSH target and use it for editing, diff review and port forwarding.
3. In an Orca terminal on that host, run mmux attach to open the session. If Orca disconnects and its remote session expires, the mmux session is still running; attach again.
4. Let one of the two create worktrees for a given repository, so you do not end up with two sets of checkouts.

cd ~/project
mmux           # on the server: open or reattach
mmux attach    # from any terminal on that host: pick a running session