AI operating system alternatives: one open-source option, four closed

Four of the five keep their code private and their configuration in the product.

• Open source. Read it, fork it, audit it.
• Agents, skills, triggers and connector rules are files in the repo, so a review is a diff you can read.
• Self-hosting is free, so leaving does not mean starting over.
• Nothing merges itself: a change request stands between agent work and the main branch.

What an AI operating system is, and who sells one

An AI operating system is the layer a company's agent work runs on. Kortix is the open-source AI Operating System, and it documents the layer in those terms: sessions are the processes, the project repo is the file system, agents and skills are the programs, connectors are the drivers, and change requests are the updates (Read the docs). Four rivals claim the same layer with vocabularies of their own.

Claude Cowork is Anthropic's agent for handing off multi-step work across your files and tools, included in Pro, Max, Team, and Enterprise plans. ChatGPT Work is OpenAI's agent for finished deliverables such as decks, reports, and analyses, powered by GPT-6. Perplexity Computer is Perplexity's general-purpose digital worker, available to Max subscribers. Microsoft Copilot is Microsoft's AI line inside Microsoft 365, with Chat, Create, Prompts, Cowork, and Work IQ as its features.

Two questions separate the five faster than any feature list. Can you run it on infrastructure you operate? And what do you keep when the relationship ends? The answers split the field one from four.

Where each one runs

Self-hosting means running the product on infrastructure you operate instead of renting the vendor's. ChatGPT Work on web and mobile runs in OpenAI's cloud, per OpenAI's help center (ChatGPT Work and Codex). Perplexity Computer is available to Perplexity Max subscribers and runs on Perplexity's infrastructure (Introducing Perplexity Computer); every task gets an isolated compute environment with a real filesystem, a real browser, and real tool integrations. Microsoft Copilot runs in Microsoft's cloud as part of Microsoft 365, where the feature set spans Chat, Create, Prompts, Cowork, and Work IQ (Microsoft Copilot). None of the three documents a self-hosted install.

Claude Cowork has the widest hosting story of the four: use a Claude account or your own Amazon Bedrock, Google Cloud, or Microsoft Foundry (Claude Cowork). That choice decides where the compute sits. The service is still Anthropic's, and Cowork's pages document no self-hosted install.

Kortix answers the question differently. Run it on Kortix Cloud, in your VPC, or on your own on-prem network. Self-host is free. Models stay yours too. Any model provider with your own keys. Or the ChatGPT plan you already pay for. The hosted four tie the model to the stack instead: Cowork runs Claude, ChatGPT Work runs GPT-6 (ChatGPT Work), Perplexity Computer orchestrates several models for reasoning, research, images, and video, and Copilot's picker selects which model answers each prompt (Microsoft Copilot Chat).

Where your configuration lives

On the hosted four, the configuration lives in the product. You connect tools, set permissions and schedule work inside each vendor's interface, and none of it is a file you can clone. Kortix takes the opposite position: the project is a git repo, and the system's settings are files in it. The starter manifest at the repo root holds the governance, naming which connectors, secrets, permissions, and skills each agent may use, and an omitted grant resolves to none, so a scoped specialist starts locked down (Kortix on GitHub).

Work lands under the same rule. Session work reaches main through a change request. Merge is default-deny for agents. On a hosted product, the matching control is the vendor's approval setting.

The difference shows up when you leave. Files move between hosts. Product settings do not. An agent's prompt, its grants and the memory it built are lines in the repo, so a new host means pointing the same repo at new infrastructure. On a hosted product, the same move means rebuilding the configuration inside the next vendor's product.

Which one fits which company

Kortix suits a company that wants its agents, memory and model choice to live in a repo it owns, because that is the product's whole design. Claude Cowork suits teams already on Anthropic plans that want to hand off tasks beside chat. ChatGPT Work suits companies standardized on ChatGPT that want deliverables in the same window. Perplexity Computer suits Max subscribers who want one system routing work across several models. Microsoft Copilot suits companies that run on Microsoft 365 and want AI bought with it.

For a buyer comparing the five, the row that decides most is the one marketing pages skip: what you own when the relationship ends. Kortix is the open-source option, and the only one of the five that answers it with a git repo you own. Choose it when owning the system matters. Choose the hosted four when a plan and a cloud you already pay for matter more.