The open-source Microsoft Copilot alternative depends on which Copilot you mean

Microsoft's Copilot line is polished, and Kortix is open source, but one search term hides four different buying decisions. GitHub Copilot completes and edits code in your editor and terminal, Copilot Studio builds conversational agents, Microsoft Copilot assists inside Word, Excel, Outlook, and Teams, and Copilot Cowork carries out multi-step work across those apps. They share a brand and almost nothing else, so there is no single open-source Microsoft Copilot alternative. The market splits by lane, and your lane decides which project you should evaluate first.

The three lanes Copilot competes in

Coding assistant. GitHub Copilot is proprietary and cloud-hosted, sold per developer seat with a free tier and paid plans, and it does not self-host. You are equipping one developer at a time. GitHub Copilot

Agent builder. Microsoft Copilot Studio is closed and cloud-only. Microsoft describes it as "an end-to-end conversational AI platform that empowers you to create agents using natural language or a graphical interface", sold per tenant through Copilot Credit packs of 25,000 credits at $200 per month or a pay-as-you-go meter. You are choosing a studio or framework to design and publish agents. Copilot Studio

Agent management at company scale. Microsoft Copilot and Copilot Cowork are the org-wide layer. Microsoft says Cowork "plans the steps, picks the right skills and apps, pauses for your approval at key checkpoints, and returns finished artifacts" across Microsoft 365 apps, billed on usage. You are choosing the system that runs a workforce of agents and governs what they do. Copilot Cowork

The lanes do not overlap. A better autocomplete plugin will not fix ungoverned agents at company scale, and an agent platform will not speed up your editor. Pick the lane that matches your problem, then read only that option set.

Lane 1: open-source coding assistants

GitHub Copilot is the lane-1 product, and it cannot be self-hosted or forked. Two open-source projects cover the work: Cline, an agent that runs in VS Code, JetBrains, the terminal, and a desktop app, and Tabby, a self-hosted completion server. Both work with models you choose.

Tabby splits its licence. Everything outside its ee/ directory is Apache-2.0, while ee/ carries a separate enterprise licence, so the Apache grant does not cover the whole server. Tabby licence

Cline reads your project, makes coordinated edits across files, watches compiler and linter errors, and shows every edit as a diff you can review or revert. It connects to Anthropic, OpenAI, Gemini, OpenRouter, Bedrock, and local models through Ollama or LM Studio, so the same tool can run against a hosted frontier model or a model on your own machine. Cline

Lane 2: open-source agent builders

Copilot Studio is closed, cloud-only, and priced per tenant. Two open-source projects let you build agents without that platform: LangGraph, a low-level orchestration framework, and Botpress, a studio whose current repository is MIT and powered by OpenAI.

LangGraph is the closest structural match to Copilot Studio because it is the orchestration layer. It provides durable execution, human-in-the-loop interruption, short- and long-term memory, and deployment tooling you assemble yourself. Copilot Studio ships a graphical studio and a publishing pipeline; LangGraph hands you primitives and expects you to build the product around them. LangGraph

Botpress is the better fit if you want a studio and accept a cloud-first product. Its current repository is MIT, and self-hosted teams run the older v12, which is dual-licensed under AGPLv3 and a Botpress proprietary licence. Botpress, Botpress v12

Lane 3: open-source agent management

Copilot Cowork is Microsoft's agentic layer over Microsoft 365. It carries out tasks across Outlook, Teams, Word, Excel, and PowerPoint, pauses for approval before sensitive actions, and bills on usage. It is closed and cloud-only. Kortix is the open-source AI Management System we recommend in this lane, and OpenWork is the closest open competitor.

Kortix is open source (Elastic License 2.0): self-host, read and modify the code. Agents, shared skills, company memory, connector config, and triggers live as files in one git repository you own. Every session runs in an isolated Linux sandbox on its own branch, and work reaches the main branch only through a change request a human reviews. Kortix works with any model provider using your own API keys and connects 3,000+ apps plus any MCP, OpenAPI, GraphQL, or HTTP API. Self-hosting is free on a laptop, VPS, VPC, or on-prem; the managed cloud starts with a free tier and a Team plan at $40 per seat per month with pooled credits (checked September 2026). Kortix on GitHub, Kortix pricing, Kortix docs

OpenWork is the more conventionally licensed option. Everything outside its ee/ directory is MIT, while the ee/ control plane sits under the OpenWork EE License, which is free for organizations of up to five users and converts each release to MIT two years after publication. Its desktop app runs on macOS, Windows, and Linux, keeps files local, and works with 50+ providers, your own keys, or local models through Ollama. OpenWork

The trade-off is where ownership sits. OpenWork keeps files on your machine and adds an organization control plane for team settings, which is the lighter setup for a small team. Kortix puts agents, skills, company memory, and connector definitions in one repo your team can diff, review, and roll back, and runs every session in its own sandbox on its own branch. A team that wants the lightest local agent should pick OpenWork, and a team that wants one governed system where agents and memory compound should pick Kortix.

Which lane are you in

• Faster code in your editor. Pick Cline or Tabby. Both self-host, and both are Apache-2.0 outside Tabby's ee/.
• Building and publishing agents for customers or staff. Pick LangGraph if you have engineering capacity and want to own the orchestration; pick Botpress if you want a studio and accept a cloud-first product.
• A governed workforce of agents across company tools. Start with Kortix: agents as files in a repo you own, any model with your own keys, free to self-host, and every change landing through human review.
• Two lanes sound true. The org-scale lane is usually the real one, because a company-wide system can absorb coding and agent building as tasks while a plugin cannot grow into governance.

Next reads: open-source Claude Cowork alternatives, Kortix vs OpenWork, and the open-source agent platform guide.

Start where your bottleneck is, then get started with open-source Kortix to run your first agent on a repo you own.