Comparison · facts verified 2026-09-12
Both projects put agents in git worktrees — that is where the similarity ends. Orca, from Stably, is the category's head project: "The AI Orchestrator for 100x builders," an ADE where you run a fleet of coding agents side by side and stay in the loop. Orbi is an unattended delivery line: a GitHub Issue goes in, a reviewed PR and a tagged Release come out, and nobody operates the middle. In Orca's own terms: Orca is how you run a fleet of agents; Orbi is how you stop having to.
THE COMPETITOR, FROM ITS OWN MATERIALS
Orca is built by Stably (the stablyai organization on GitHub) and describes itself, verbatim, as:
“The AI Orchestrator for 100x builders. Run Codex, ClaudeCode, OpenCode or Pi side-by-side — each in its own worktree, tracked in one place.”
Orca README · verified 2026-09-12
“Orca is the ADE for working with a fleet of parallel agents. Run any coding agent with your own subscription. Available on desktop, mobile and remote runtime.”
Orca repository “About” description, same wording on onorca.dev · verified 2026-09-12
The scale is real and worth respecting: the repository was created on 2026-03-17 and reached 66,832 stars and 4,391 forks within six months (GitHub API, measured 2026-09-12) — the fastest-growing project in this comparison set, under an MIT licence. The documented surface matches the self-description: a desktop app for macOS, Windows and Linux, a mobile companion for iOS and Android, a CLI (“Agents drive Orca too — script every workflow with orca worktree create, snapshot, click, and fill”), and parallel git worktrees so several agents can work at once. The review loop is operator-centered by design: “Drop comments on any diff line and ship them back to the agent — review, edit, and commit without leaving Orca.”
Sources: Orca README (self-description, CLI, worktrees, platforms, diff annotation); GitHub API repository record (stars, forks, creation date, MIT licence) — verified/measured 2026-09-12.
THE OPERATING SURFACE
The two products agree on one thing — agents isolated in git worktrees — and diverge on who does the operating. Cells we could not verify in Orca's official materials read “Not verified”, never “No”.
| Dimension | Orbi | Orca |
|---|---|---|
| Positioning | Unattended delivery line: GitHub Issues in, tagged Releases out | “The AI Orchestrator for 100x builders” — the ADE for a fleet of parallel agents (official) |
| The human's place | Outside the loop: open the Issue, apply ai-ready, read the evidence | In the middle, operating: annotate diffs, steer agents, “review, edit, and commit without leaving Orca” (official) |
| Task entry | GitHub Issue + ai-ready label | Desktop app, mobile companion, and CLI (orca worktree create); no unattended queue documented |
| Opens the delivery PR | Yes | Not verified — browsing PRs in-app is documented; an agent opening the delivery PR is not |
| Independent review (can edit code and rerun tests) | Yes — an independent session repairs the code and reruns the suite | Not verified — the documented review is a human annotating the diff |
| Auto-merge | Yes — merges the exact reviewed head | Not verified — “merge the winner” refers to comparing parallel agent outputs, not a documented PR auto-merge |
| Tag / Release | Yes — freezes the SHA, tags, publishes the Release | Not verified |
| Form factor | Self-hosted CLI + systemd on your machine; hosted Cloud pilot | Desktop (macOS/Windows/Linux), mobile (iOS/Android), remote runtime; CLI |
| Licence | fair-code (Sustainable Use License) | MIT |
Sources: Orca README; onorca.dev; Orbi documentation — verified 2026-09-12. “Not verified” = we found no official statement, not a statement of absence.
A DIMENSION YOU CAN COUNT
Two repositories can both be active and still mean different things by it. These are the counts on verification day — they move daily; the shape is the point. No quality judgment is implied in either direction: the numbers describe different design goals.
| Count (GitHub API, 2026-09-12) | Orbi | Orca |
|---|---|---|
| Stars / forks | 95 / 10 | 66,832 / 4,391 |
| Open issues + PRs (open issues) | 34 (32) | 5,867 (2,815) |
| Merged PRs in the 19 days to 2026-09-12 | 294 merged since its first commit day (2026-08-24) | Not measured — its issue tracker serves a 66.8k-person community as a product front door, so raw counts are not comparable |
| Releases | 18 GitHub Releases in the same 19 days | Ships near-daily (the README says “we ship daily”) |
“Busy” and “converged” are different things. A 66.8k-star project's tracker is a community commons; a delivery line's tracker is a work queue. Each number is what its design wants it to be.
Sources: GitHub API — stablyai/orca; GitHub API — orbi-build/orbi; GitHub search API for open-issue counts — measured 2026-09-12.
STATED PLAINLY, BECAUSE IT MATTERS
If your requirement is an OSI-defined open-source licence, Orca's MIT wins and no comparison copy should blur that. Orbi is fair-code — the Sustainable Use License: you can self-host it, inspect it, and run it on your own infrastructure, but commercial redistribution is restricted so the project can keep being maintained. For a self-hosting audience that is a genuine Orbi disadvantage on paper; we state it here rather than around it. The trade it buys is the one every fair-code project bets on: continued maintenance of the tool your delivery line depends on.
Sources: Orca README (MIT badge) and GitHub API licence record; Orbi LICENSE.md (Sustainable Use License) — verified 2026-09-12.
AN HONEST READ
This is not a ranking. The two products answer different questions, and many teams will reasonably want both.
PROVENANCE
This page is a dated snapshot: every factual claim above was checked on 2026-09-12. Star, fork and issue counts move daily; re-read the linked sources before you bet architecture on them.
ai-ready, independent review, exact-head merge, tag + Release
verified 2026-09-12
docs.orbi.build
FAIR-CODE CORE
Run a fleet of agents with Orca; hand the delivery line to Orbi. If the second is the job — GitHub Issues becoming reviewed PRs and tagged releases while you do something else — Orbi is free to self-host, and the keys stay yours.