We’re joining CoreWeave to double down on open source and scale molab
TL;DR Marimo is joining CoreWeave. We’re continuing to build the open-source marimo notebook, while also leveling up molab with serious compute. Our long-term mission remains the same: to build the world’s best open-source programming environment for working with data.
marimo is, and always will be, free, open-source, and permissively licensed.
I started work on marimo nearly four years ago with a belief that Python developers deserved dramatically better tools for working with data. My experience researching and developing vector embedding methods, largely in Jupyter notebooks, motivated me to create something better. As I wrote last year, when we announced our seed fundraise (led by Anthony Goldbloom and Shyam Mani at AIX):
Jupyter notebooks were essential to my work, because they let me see my data while I worked on it — but they were also extremely frustrating. Hidden state led to hidden bugs (over a third of the 10 million Jupyter notebooks on GitHub fail to reproduce), the JSON file format made them hard to use in Python codebases, and the final documents lacked interactivity. While Jupyter notebooks are widely used for AI/ML development, STEM, and data engineering, now more than ever, there’s growing consensus that this kind of work shouldn’t be done in error-prone scratchpads.
Myles and I teamed up, and the result was marimo: a programming environment that feels like a next-gen reactive Python notebook (eliminating hidden state), but is stored as pure Python that can be reused as scripts, modules, and apps. We launched marimo to the public in January 2024. Fast forward to today, and marimo is rapidly becoming the gold-standard open-source programming environment for AI, ML, data, and science, with more than 1M monthly downloads, 16.6k GitHub stars (more than Jupyter), nearly 200 GitHub contributors, 3k+ Discord members, and 680k+ YouTube views. Along the way, we made it possible to run marimo entirely in the browser with WebAssembly, were featured in Nature, launched molab (our free, cloud-hosted notebook), sprinted on AI-assisted coding (becoming one of the first editors to implement the Agent Client Protocol).
In addition to growing marimo, we also grew marimo team from two to eight, adding the inimitable Johnny Chin, Vincent Warmerdam, Shahmir Varqha, Dylan Madisetti, Trevor Manz, and Shyam Mani — all of whom joined marimo organically, through their contributions to our open-source and our shared passion for making better tools for humans working with data.
To our community, from all of us on the marimo team: marimo wouldn’t be where it is today without your help. Your code contributions and feedback shape marimo for the better; the awesome notebooks you make, and the blue-sky ideas you share, inspire us to keep building. Thank you!
Joining CoreWeave
Marimo and the entire marimo team is joining CoreWeave, the Essential Cloud for AI. CoreWeave’s vision for marimo is the same as ours: to make marimo the defacto open-source programming environment for AI, ML, and data work.
Through our conversations with Lukas Biewald (Co-founder and GM of Weights and Biases), Chen Goldberg (SVP, Engineering, formerly GM/VP Kubernetes), and others, it became clear that CoreWeave shared our deep respect for developers, open-source software, and community. CoreWeave is fully committed to not only keeping marimo free, open-source, and permissively licensed, but also accelerating its development. Our number one priority together is to continue developing and growing the open source marimo notebook. Thanks to the awesome scale of the cloud platform that CoreWeave has built, we’ll also power molab with CoreWeave’s cloud services, and make it purpose-built for the AI workloads of the future.
What’s next
Our acquisition lets us keep doing what we’ve already been doing — building marimo, now with the resources and backing of a leading public company building an essential cloud for AI and data. It also gives us the ability to scale molab and to offer our community GPU-accelerated compute services.
Having worked on open-source software for the past seven years, from TensorFlow to CVXPY and now marimo, I know how important trust and communication are to the health of open-source projects. To the marimo community — we’re committed to developing in the open, for you and alongside you, and to keeping our tools free and open-source. The marimo notebook will always be free, open-source, and permissively-licensed.
All of marimo team is staying together, and you can find us in the usual places — come hang out on Discord, or drop us a comment on YouTube.
We’re hiring!
Working on marimo has truly been a dream. The marimo team is excited to be able to continue pouring our hearts and souls into this project, for many years to come. If building the future of marimo excites you, get in touch — we’re hiring!
P.S Check out our latest release (0.17.3)!
FAQ
Will marimo remain free, open source, and permissively licensed?
Yes.
Will molab remain free?
Yes, and we’ll be offering a more generous free tier; the ability run on larger instances and GPUs, and longer-lived sessions
How does this affect marimo’s roadmap?
Our open-source roadmap remains the same, staffed by the same people. Joining CoreWeave also allows us to grow the core open-source team: we’re hiring!
How does this affect molab’s roadmap?
We’ll get substantially more resources, both compute and engineering, to make molab the world’s best cloud hosted programming environment for AI and data work. Stay tuned. There are many hard engineering challenges involved; we’re hiring!
I’m behind the times, what’s marimo and how do I use it?
marimo is an open-source reactive notebook for Python that is designed specifically for working with data. marimo notebooks are stored as pure Python (version with Git), shareable as data apps, executable as scripts or pipelines, reproducible in execution and packaging, have SQL built-in, and make it easy to connect to your own databases and data lakes. marimo has no dependencies on Jupyter or IPython, and is built entirely from scratch.
marimo was originally developed with input from scientists at Stanford and developers in industry. With over 1M+ monthly downloads, 16k+ GitHub stars, and nearly 200 contributors, marimo is now used broadly at companies and universities large and small.
Get started with marimo by with pip install marimo && marimo tutorial intro.’
Will Vincent still make YouTube videos?
Yes!
