Comparison · OS.js alternative

Vulos as an OS.js alternative

They are not the same kind of thing, and that is the most useful thing to say first. OS.js is a JavaScript web desktop you run on a server you already have. Vulos is the operating system of the machine itself. If a windowed UI in a browser tab is what you need, OS.js may well be the better answer — this page tries to make that call easy either way.

Every OS.js fact below was read from OS.js's own site, repository, licence file and manual on 10 August 2026. Projects move; if something here has gone stale, the sources are listed at the bottom so you can check for yourself.

What OS.js actually is

OS.js describes itself as “an open-source JavaScript web desktop platform with a window manager, application APIs, GUI toolkit, filesystem abstractions and much more”. It is a client that runs in any modern browser, paired with a Node/Express server process — it cannot run purely client-side, because that server owns routing, sessions, authentication and the virtual filesystem.

Its manual puts the install requirement plainly: “The only dependency is Node 12 or later”. You clone it, npm install, start the server and open http://localhost:8000. There is also a published Docker image, osjs/osjs:latest. The two documented extension seams are a custom VFS adapter and a custom authentication adapter, which is how you point it at storage and identity you already run.

The licence is BSD 2-Clause — the LICENSE file in the repository reads “BSD 2-Clause License / OS.js - JavaScript Cloud/Web Desktop Platform / Copyright (c) Anders Evenrud”. That is about as permissive as open source gets: keep the copyright notice and you can put it in a commercial product.

What OS.js is genuinely good at

  • It is small and it is a library, not a commitment. One Node process and one port, dropped next to whatever else you already run. Nothing about your machine changes.
  • BSD-2 is the most permissive licence in this comparison. If you are embedding a desktop UI into a product you ship to customers, that matters more than any feature.
  • The adapter seams are the point. Custom VFS and custom authentication adapters mean OS.js can be a friendly window onto systems that already exist — an S3 bucket, a NAS, a corporate SSO — without those systems moving anywhere.
  • It has been at this since 2013 and the codebase is readable, well-separated JavaScript. It is a good thing to learn from and a good thing to fork.

One thing to know before you pick it

Development has slowed. As of 10 August 2026, the main os-js/OS.js distribution repository's last tagged release is 3.1.12, from 24 July 2021, and its last commit was December 2022. The org's separate package repositories have seen work since — osjs-client in April 2024, osjs-xterm-application in November 2025 — so it is not abandoned, but it is not moving quickly either. That is a fair trade if you want something stable to fork, and a real risk if you want an upstream that ships.

What Vulos actually is

Vulos is a sovereign personal server with a browser-native desktop, running on a single machine — bare metal, a VM, or a VPS. The shell is a React app; the backend is a single Go binary with SQLite underneath, so a basic install needs no external database. You reach it from any browser, but the thing you are reaching is a computer you own.

The distinction that matters against OS.js: Vulos ships as an OS image that boots the box. It owns the disk, the boot chain and the network namespaces. Each installed app runs in its own Linux network namespace. Native Linux applications launch into their own virtual display and stream into a browser window over WebRTC on demand, then stop when you close the window. The app registry is signed with Ed25519 against an offline root key baked into the image, and installs fail closed— unsigned or tampered entries are refused.

There is no central Vulos service behind any of it. The assistant and every other AI feature run on your box, mediated by llmux, using a local model or your own provider key. The status page says the quiet part out loud: there is nothing of ours to be down, because we do not run anything your box depends on. Vulos is licensed MIT OR Apache-2.0.

Side by side

 OS.jsVulos
CategoryWeb desktop platform — a UI layer in the browserOperating system for a machine you own
LicenceBSD 2-ClauseMIT OR Apache-2.0
What you installA Node app (Node 12+), or the osjs/osjs Docker imageAn OS image flashed to disk or booted from USB — or Docker, to try it
Runs alongside your other software?Yes — it is one process on a server you already haveNot really — it expects the machine (x86_64/arm64, UEFI)
BackendNode / Express: routing, sessions, auth, VFSOne Go binary + SQLite; no external database for a basic install
Storage modelVFS abstraction over adapters you configureThe box's own disk, with per-user isolation enforced on-box
Native Linux appsNot in scope — apps are OS.js applicationsStreamed into browser windows on demand (virtual display + WebRTC)
How apps are distributedAs npm packages, per the project's own READMEEd25519-signed registry against an offline root key; fails closed
Upstream pace (checked 10 August 2026)Last tagged release 3.1.12, July 2021; package repos updated occasionally sinceFirst tagged release v0.1.0, 7 August 2026 — very new

Table scrolls sideways on narrow screens.

Where Vulos is weaker

If we only listed our own strengths this page would not be worth reading. These are the honest gaps against OS.js:

  • Vulos is far newer. OS.js has been developed since 2013. Vulos's first tagged public release, v0.1.0, is dated 7 August 2026. Longevity is a feature and we do not have it yet.
  • It asks for the whole machine. OS.js is npm install beside your other services. Vulos wants a box: x86_64 or arm64 with UEFI firmware, 2 GB RAM minimum, 10 GB of disk. If you just want a desktop UI in front of an existing server, that is a lot of ceremony for the thing you actually wanted.
  • You must disable Secure Boot. The Vulos bootloader is not signed for Secure Boot today, so a Secure-Boot-enabled machine will refuse to boot it. That is a real limitation, documented in our own install guide.
  • There is no drop-in-to-an-existing-app story. OS.js's VFS and auth adapters are a deliberate seam for fronting systems you already run. Vulos has no equivalent: it is the system.
  • Multi-instance sync is narrower than the design. Our own architecture doc states it plainly: cr-sqlite is not integrated, so the leaderless whole-database CRDT merge does not run today. What is real is a pure-Go CRDT for the app registry, synced over mDNS on the same LAN, plus an S3 snapshot of one instance's database file — not a cross-node merge.
  • ARM support has a sharp edge. The published ARM64 image is a generic UEFI target. Raspberry Pi and PinePhone need a build you produce yourself.

Which one should you pick

Pick OS.js if…

  • You want a windowed UI on top of servers, storage and identity you already run.
  • You are embedding a desktop metaphor into your own product and want the most permissive licence available.
  • You need it to sit beside your existing services, not replace them.
  • A stable, slow-moving, forkable codebase is a feature for you rather than a worry.

Pick Vulos if…

  • You want the machine your work lives on to be one you can open, read and replace.
  • You want a whole computer — files, apps, mail, an on-box assistant — not a UI layer you then have to fill.
  • You want native Linux applications available in the browser without a permanent remote-desktop session.
  • You want signed, fail-closed app installs rather than trusting a package registry.
  • You accept a young project in exchange for owning the whole stack.

Sources, checked 10 August 2026