Livebook is a web application for writing interactive and collaborative code notebooks. It features:

• A deployable web app built with Phoenix LiveView where users can create, fork, and run multiple notebooks.

• Each notebook is made of multiple sections: each section is made of Markdown and Elixir cells. Code in Elixir cells can be evaluated on demand. Mathematical formulas are also supported via KaTeX.

• Persistence: notebooks can be persisted to disk through the .livemd format, which is a subset of Markdown. This means your notebooks can be saved for later, easily shared, and they also play well with version control.

• Sequential evaluation: code cells run in a specific order, guaranteeing future users of the same Livebook see the same output. If you re-execute a previous cell, following cells are marked as stale to make it clear they depend on outdated notebook state.

• Custom runtimes: when executing Elixir code, you can either start a fresh Elixir process, connect to an existing node, or run it inside an existing Elixir project, with access to all of its modules and dependencies. This means Livebook can be a great tool to provide live documentation for existing projects.

• Explicit dependencies: if your notebook has dependencies, they are explicitly listed and installed with the help of the Mix.install/2 command in Elixir v1.12+.

• Collaborative features allow multiple users to work on the same notebook at once. Collaboration works either in single-node or multi-node deployments - without a need for additional tooling.

There is a screencast by José Valim showing some of Livebook features. Otherwise, here is a peek at the "Welcome to Livebook" introductory notebook:

The current version provides only the initial step of our Livebook vision. Our plan is to continue focusing on visual, collaborative, and interactive features in the upcoming releases.

Usage

For now, the best way to run Livebook is by cloning it and running it locally:

$ git clone https://github.com/elixir-nx/livebook.git
$ cd livebook
$ mix deps.get --only prod
$ MIX_ENV=prod mix phx.server

You will need Elixir v1.11 or later.

Keep in mind that Livebook is built to document and execute code. Anyone with access to a Livebook instance will be able to access any file and execute any code in the machine Livebook is running.

We will work on other distribution modes (escripts, Docker images, etc) once we start distributing official releases.

License

Copyright (C) 2021 Dashbit

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as
published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.

Rationale

Note: this section explains our rationale behind choosing AGPL v3 and does not give you any rights beyond those listed in the LICENSE file.

Livebook's LICENSE does not impact your own notebooks. All of the notebooks you write belong to you and under the license of your choice (if any). However, if you make changes to Livebook source code, your modifications must be available to those using your version of Livebook. For example, if you change Livebook to run it exclusively inside your own company, your changes only have to be available within the company itself. However, if you modify Livebook in order to build your own service with users from different locations and from multiple companies, then you must link back to Livebook and make the modified source code available using the same license as Livebook.

At the end of the day, it is not different from using a database that is AGPL licensed: your data, the queries you write, and the applications that talk to the DB are all distinct and separate from the database itself. However, if you want to add new functionality to the database and charge a fee for others to use it, then you need to make your derived source code public too.

Dashbit has released many open source projects throughout the years under the Apache 2 License. However, for Livebook, we chose to use AGPL v3 since Livebook is an application and not a library. This means developers will be running it directly instead of bringing it as a dependency into their own projects and we would like improvements done directly to the application to be available to the Livebook community at large, whenever possible, as Livebook itself is. Other projects that use AGPL are RStudio and ScyllaDB.

Further reading for those interested:

• GNU Affero General Public License
• Understanding the AGPL: The Most Misunderstood License