Open Source Agent Workspaces 2026: 8 Tools Compared

Every few weeks another tool appears for running coding agents in parallel, and the names in search queries change faster than the comparison articles do. This guide covers eight of them that come up repeatedly: cmux, Superset, Orca, Paseo, Herdr, T3 Code, Goose, and Warp.

Every fact below was checked against each project’s own repository, release assets, licence file, or product site on 22 August 2026. Star counts and release numbers move; the licences and platform support are the parts worth reading closely.

What These Tools Actually Do

The eight tools split into three jobs, and comparing them without that split produces nonsense.

• Agent workspaces run other people’s CLI agents and give you somewhere to watch, review, and steer them. Superset, Orca, Paseo, and T3 Code are here.
• Terminal runtimes keep agent terminals alive and organised without imposing a GUI workflow. cmux and Herdr are here.
• Agents and agent platforms are the thing being run, or the platform around it. Goose is an agent, and Warp is a terminal with its own agent plus a cloud orchestration product.

The categories nest, so the comparison only makes sense within a row: Goose can run inside Orca, Claude Code can run inside cmux, and Goose and Herdr are not substitutes for each other at all.

Quick Answer

• Best macOS-native terminal for agents: cmux
• Best cross-platform terminal runtime: Herdr
• Best feature-dense agent IDE: Orca
• Best phone-first remote control: Paseo, with T3 Code close behind
• Best worktree workspace with a permissive-ish source model: Superset, if Elastic License 2.0 is acceptable
• Best general-purpose local agent: Goose
• Best terminal with a cloud agent platform: Warp
• Best workspace where the agent’s work and your documents live together: Nimbalyst

Comparison Table

The eight tools in this guide, with Nimbalyst on the last row for reference.

Tool	Type	Platforms	Licence	Worktree isolation	Mobile access
cmux	Native terminal for agents	macOS	GPL-3.0-or-later, commercial licence offered	Via your own git workflow	iOS app in beta
Superset	Desktop agent workspace	macOS, Linux (AppImage)	Elastic License 2.0 (source-available)	Yes, one worktree per workspace	Remote workspaces via CLI and phone
Orca	Desktop agent IDE	macOS, Windows, Linux	MIT	Yes, one worktree per agent	iOS App Store, Android APK
Paseo	Local daemon plus clients	macOS, Windows, Linux, web, CLI	AGPL-3.0	Yes	iOS and Android apps
Herdr	Terminal runtime and multiplexer	macOS, Windows, Linux	Apache-2.0	Via your own git workflow	Reattach over SSH
T3 Code	Agent harness control surface	macOS, Windows, Linux, web	MIT	Yes, native git worktree support	iOS and Android apps
Goose	General-purpose local agent	macOS, Windows, Linux	Apache-2.0	Not its job	No
Warp	Terminal plus cloud agent platform	macOS, Windows, Linux	AGPL-3.0 client, UI crates MIT; hosted Oz is commercial	Not the model	No
Nimbalyst	Visual agent workspace	macOS, Windows, Linux	MIT for individual-use features	Optional, one click per session	iOS companion app

cmux

cmux is a native macOS terminal built in Swift and AppKit on top of libghostty, aimed squarely at people running several coding agents at once. Its own README is blunt about the philosophy: “cmux is a primitive, not a solution.”

The features that justify it over a stock terminal are the sidebar and the notifications. Vertical tabs show the git branch, linked PR status, working directory, listening ports, and the latest notification text per workspace. When an agent is waiting on you, its pane gets a blue ring and the tab lights up, which solves the problem that Claude Code’s own notification body never tells you which session is asking. It also reads your existing Ghostty config, ships a scriptable in-app browser ported from agent-browser, and has a cmux claude-teams command plus a CLI and socket API for automation.

• Platforms: macOS only. The published release is a single macOS disk image, with remote daemon binaries for Linux and macOS hosts you SSH into. An iOS app is in beta.
• Licence: GPL-3.0-or-later, with a commercial licence offered for organisations that cannot comply with GPL terms.
• Maintenance: active, with commits on the day we checked.

Where it falls short: it is a terminal, so there is no file tree, no diff viewer, and no task tracking. The omission is deliberate. If you want a GUI that structures the work, cmux is the wrong shape, and the author says as much.

Superset

Superset is a desktop application built around running many CLI agents at once, each in its own git worktree with its own branch, terminal, and environment. Beyond the parallel workspaces it has a built-in diff viewer you can comment in and commit from, an in-app browser with per-worktree port detection, scheduled automations, remote workspaces on other machines, a CLI and SDK, and Slack and Linear entry points for spinning up a workspace from a message or an issue.

• Platforms: the latest release publishes macOS disk images for Apple Silicon and Intel plus a Linux AppImage. There is no Windows build.
• Licence: Elastic License 2.0. The source is public and the desktop app is free to run on your own machine, but ELv2 is source-available rather than OSI open source.
• Maintenance: active, releasing frequently.

Where it falls short: the licence rules it out for anyone with a hard open source requirement, and Windows users have nothing to install.

Orca

Orca calls itself an ADE, an Agent Development Environment, and it is the most feature-dense tool in this comparison. Its own line is “Run Codex, ClaudeCode, OpenCode or Pi side-by-side, each in its own worktree, tracked in one place.”

The distinctive parts are design mode, where clicking a UI element in an embedded Chromium window sends its HTML, CSS, and a cropped screenshot into the agent prompt; SSH worktrees that run agents on a remote box with full file editing and port forwarding; diff annotation, where comments on a diff line go back to the agent; and GitHub and Linear browsing inside the app so you can open a worktree straight from an issue. It also tracks Claude and Codex usage and rate-limit resets and lets you hot-swap accounts.

• Platforms: macOS, Windows, and Linux desktop builds, an iOS app on the App Store, and an Android APK from GitHub releases.
• Licence: MIT.
• Maintenance: active, with a release on the day we checked. The README points at the changelog as the more complete feature list, because they ship daily.

Where it falls short: the surface area is large, and a tool that ships daily moves under you. If you want something small and stable, this is not it.

Paseo

Paseo inverts the usual architecture. A local daemon runs on your machine and owns the agent processes, and every client is a view onto it: an iOS app, an Android app, an Electron desktop app, a web client, and a CLI. Agents run with your full dev environment, your tools, your configs, and your skills. It treats Claude Code, Codex, GitHub Copilot, OpenCode, and Pi as interchangeable providers, with worktrees so parallel work does not collide, and voice input for hands-free prompting.

• Platforms: desktop builds for macOS, Windows, and Linux, plus iOS, Android, web, and CLI clients.
• Licence: AGPL-3.0, with third-party components under their own licences.
• Maintenance: active.

Where it falls short: AGPL is a hard constraint for some companies, and the daemon-plus-client model means one more thing to keep running and updated. Our closer look at Paseo alongside two similar tools is in Nimbalyst vs Openwork vs Paseo.

Herdr

Herdr is a single Rust binary that runs inside whatever terminal you already use, and it is the cleanest answer to “I want cmux but not on macOS.” It runs as a background server holding the terminals, so agents survive the lid closing, a dropped network, or a restart, and you reattach from any terminal or over SSH. Every pane is marked working, blocked, or idle, so the stuck agent announces itself. Agents can drive Herdr through its CLI and socket API, spawning panes and prompting each other, and there is a plugin marketplace.

• Platforms: macOS, Windows, and Linux binaries, installable through a shell script, Homebrew, mise, or PowerShell.
• Licence: Apache-2.0.
• Maintenance: active. Version 0.8.2 shipped on 19 August 2026, from a repository first published in March 2026.

Where it falls short: like cmux, it owns terminals and nothing else. Someone who wants Herdr plus a file browser and git views is asking for a different category of tool, and that gap is where a workspace earns its place.

T3 Code

T3 Code, from the T3 team, describes itself as an agent harness control surface. The pitch is remote control of the agents already installed on your machine, with a mobile app as a first-class client rather than an afterthought. It works with your existing subscriptions to Claude Code, Codex, Cursor, Grok Build, and OpenCode, and it has native git worktree support so an agent works in a separate checkout while your main working directory stays untouched.

You can try it without installing anything by running npx t3@latest, which starts the backend and the local web app.

• Platforms: desktop builds for macOS via Homebrew, Windows via winget, and Arch Linux via the AUR, plus a web app and iOS and Android apps.
• Licence: MIT.
• Maintenance: active, but early. The README says “We are very very early in this project. Expect bugs” and that the team is mostly not accepting contributions yet.

Where it falls short: the project’s own warning is the fairest summary. It is also explicit that big feature contributions will not be accepted, so the fork-it-yourself path is the intended escape hatch.

Goose

Goose is the odd one out here, and worth including precisely because people compare it to the others. It is a general-purpose AI agent that runs on your machine, described by its own README as “not just for code, use it for research, writing, automation, data analysis, or anything you need to get done.” Written in Rust, it ships a native desktop app, a full CLI, and an API for embedding. It works with 15 or more providers including Anthropic, OpenAI, Google, and Ollama, connects to 70-plus extensions over MCP, and can use existing Claude, ChatGPT, or Gemini subscriptions through ACP.

Goose moved to the Agentic AI Foundation at the Linux Foundation, which is a meaningful governance signal if you are betting a workflow on it.

• Platforms: macOS, Windows, and Linux, desktop app and CLI.
• Licence: Apache-2.0.
• Maintenance: very active, with foundation governance and a documented custom-distribution path.

Where it falls short as an answer to “control and granularity,” which is how people usually phrase the Goose complaint: Goose gives you an agent and a chat surface, not a board of parallel sessions with per-file review. The tool you want alongside it is a workspace that runs it.

Warp

Warp is the one with a commercial cloud product attached. It positions itself as an agentic development environment born out of the terminal, with three pieces: the Warp terminal, its built-in agent Oz, and Oz as an orchestration platform for cloud agents. It also runs third-party CLI agents such as Claude Code, Codex, and Gemini CLI.

One point is worth correcting, because plenty of comparisons still get it wrong in both directions. Warp open sourced its client codebase in April 2026, and it now lives in the warpdotdev/warp repository: the warpui_core and warpui crates under the MIT licence, and the rest of the repository under AGPL v3. What is not in that repository is the hosted Oz service, which is the paid commercial product. If you read a page saying Warp is closed source, it predates the change; if you read one saying Warp is fully open source, it skips the hosted half.

• Platforms: macOS, Windows, and Linux.
• Licence: AGPL v3 for the client, MIT for the two UI crates. Hosted Oz is a commercial service.
• Pricing: a free tier, then paid plans starting around 18 dollars per month for individuals, a higher-volume individual plan, per-seat business pricing, and custom enterprise pricing. Plans are credit-based, so check the current pricing page before committing.

Where it falls short: the credit model, and AGPL on the client is a stricter obligation than the MIT and Apache options above if you plan to build on the code. Our side-by-side is at Nimbalyst vs Warp.

Nimbalyst

Nimbalyst is the open source visual workspace for building with Codex, Claude Code, and more. It runs parallel agent sessions with optional one-click git worktree isolation, a session board for what is running and what is waiting, and file-by-file diff review before you accept anything.

What separates it from the seven above is what sits next to the sessions. The markdown specs, diagrams, mockups, data models, spreadsheets, tasks, and code all live in the same workspace, deeply linked, and your agents read and edit them in place. The complaint behind the searches that led here is rarely about terminals. It is that the agent runs in one place while the plan, the spec, and the diagram live in five others.

• Platforms: macOS, Windows, and Linux, plus an iOS companion app.
• Licence: MIT licensed for individual-use features. Details on the open source page.
• Agents: Claude Code and Codex side by side, OpenCode supported, Gemini CLI in alpha.

Where it falls short: if all you want is a fast terminal with better notifications, Nimbalyst is more product than you need, and cmux or Herdr will make you happier.

How to Choose in Five Questions

1. Do you want a terminal or an application? Terminal people should go straight to cmux on macOS or Herdr anywhere. Everything else in this list will feel like a cage.
2. Does the licence have to be OSI-approved? If so, Superset is out; Elastic License 2.0 is source-available rather than OSI open source. Orca and T3 Code are MIT, Herdr and Goose are Apache-2.0, Paseo and the Warp client are AGPL-3.0, cmux is GPL-3.0-or-later, and Nimbalyst is MIT for individual-use features.
3. Which operating system? Superset has no Windows build and cmux is macOS only. Everything else covers all three.
4. Do you need it from your phone? Paseo, T3 Code, and Orca all ship mobile clients. Nimbalyst has an iOS companion app.
5. Are you supervising agents, or living with the artefacts they produce? Supervision is well served by any of these. If the specs, diagrams, mockups, and tasks matter as much as the diffs, that is the gap a workspace fills.

For the Codex-specific version of this question, including which of these run on Linux, see Best Codex GUI Tools and Desktop Apps. For the Claude Code version, see Best Claude Code GUI Tools.