Fizzy is an open-source kanban tool for tracking issues and ideas, published by 37signals as a Ruby on Rails application, and it is aimed at teams that want a fast, simple board together with the source code and the option to run that board on their own server.

What it is

Fizzy is the source code of the kanban tracking tool that 37signals runs at fizzy.do. It is a Ruby and Rails application built with Hotwire, and it sits in the Business Software / Project & Work Management category. The repository ships the full application rather than a plugin or a client, so the same codebase supports a hosted board and a board you operate yourself. Alongside the source, the project maintains a set of operational guides: a Docker deployment guide in docs/docker-deployment.md, a Kamal deployment guide in docs/kamal-deployment.md, and a development guide in docs/development.md.

The concrete problem it solves is ownership and modifiability of a working kanban board. A team that wants kanban tracking normally signs up for a service it cannot inspect, cannot change, and does not run. Fizzy gives that team two paths out: deploy the pre-built Docker image when no code changes are needed, or deploy with Kamal when the team wants to alter the code and push those changes to its own server. The README describes itself as "Kanban as it should be. Not as it has been," and the tagline frames the goal as modern kanban that is fast, fun, and refreshingly simple. Because the licence and the source are published, the board becomes something a team can fork rather than merely rent, and the 1,193 forks on the repository show that teams do exactly that.

Key capabilities

• Tracks issues and ideas on kanban boards, which the README and the project description both name as the core purpose.
• Ships a pre-built Docker image for self-hosting, documented in docs/docker-deployment.md.
• Supports Kamal-based deployment for installations whose code has been customized, documented in docs/kamal-deployment.md.
• Documents a local development setup in docs/development.md for people modifying the application.
• Built on Rails with Hotwire, as the repository topics rails, ruby, and hotwire indicate, giving interactive board updates without a separate heavy JavaScript application.
• Accepts outside contributions, with code submissions expected to follow the project's style guide in STYLE.md.
• Offers a hosted instance at fizzy.do for teams that do not want to operate the deployment themselves.

Who uses it and how

• Product and engineering teams that track issues and ideas on kanban boards and want the board to be part of their own infrastructure rather than a third-party account.
• Self-hosters who have a server capable of running Docker and are willing to configure the installation options the Docker deployment guide requires.
• Development teams that fork the repository and deploy their modified version with Kamal, a workflow the project explicitly recommends for anyone needing more flexibility than the pre-built image allows.
• Rails and Hotwire developers who want to read or extend a production Ruby application, working from docs/development.md and submitting changes against STYLE.md.
• Teams evaluating self-hosted kanban tooling, for whom the repository's 8,202 stars and 1,193 forks are a rough signal of how widely the code has been picked up.

Getting started

Two documented routes exist. Teams that do not need code changes deploy the project's pre-built Docker image following docs/docker-deployment.md, while teams that want to modify the code deploy with Kamal following docs/kamal-deployment.md. Local development setup is covered in docs/development.md.

How it compares

The facts provided name no comparable tools, and no list of paid products that Fizzy replaces has been supplied, so on the evidence here it stands alone in this registry. What can be said is that it is a self-hostable, source-available Rails application published by 37signals, with a hosted counterpart at fizzy.do, rather than a purely hosted service or a closed client for someone else's backend.

When to use it — and when not to

A self-hoster must have a server on which Docker can run and must configure the installation options the deployment guide describes, so this is not a zero-operations choice for a team without any server or deployment capacity. The licence should be checked before adoption: the README states that Fizzy is released under the O'Saasy License, but the repository metadata reports the licence as NOASSERTION, meaning automated tooling does not recognise it as a standard open-source licence, and anyone planning commercial use or redistribution should read LICENSE.md directly. The README excerpt provided also does not document the database, storage, or mail delivery requirements of a deployment, so those details need to be confirmed in the deployment guides before committing to the platform.