fkorotkov

It won’t and I think it will thrive even more. ;)

You’ll be pleasantly surprised. Updates in the coming weeks.

> In the coming weeks, we will relicense all of our source-available tools, including Tart, Vetu and Orchard under a more permissive license. We have also stopped charging licensing fees for them.

You are checking the wrong Cirrus Labs.

We were 100% bootstrapped with no outside capital or support/advisory.

Thank you! Full journey is too long for a comment here.

It was hard and I was lucky with my previous pre-IPO gigs at Airbnb and Twitter so I had some bootstrap fund. In retrospective a dev tools startup in 2017 with no network and no VC support was a crazy idea but I was young and didn’t think thought too much.

Then it was long 8 years of raw work and constant questioning this choice. Then finally a third component: luck. In 2024-2025 it kind of grew organically due to market changes and back in October 2025 I finally stopped questioning the future of Cirrus Labs.

My only advice if I may, try to get your first dollar from your startup while you are employed.

Just want to note that we will continue maintaining and improving our virtualization solutions actually with even greater attention. SaaS options like Cirrus CI and Cirrus Runners will eventually wind down so we can focus on incorporating pieces internally.

Thank you! Cirrus CLI is still around and can run your tasks locally in either Podman or Docker. Can also be used in any other CI.

Cirrus CI was on a downhill in terms of users and revenue for years now. Most of the customers moved to GHA already.

Plus migration is super easy with Cirrus CLI -- tool to run our CI task definitions locally or in any CI. See https://github.com/cirruslabs/cirrus-cli

I agree! It’s a pity we didn’t make commercially successful.

Thank you for kind words! But we were planning to shut down Cirrus CI anyways. The usage was lower and lower due to GitHub Actions to the point this product was not bringing revenue. As a bootstrapped company we wouldn’t have an option to have a not profitable offering.

Can you elaborate on what got “broken” on Tahoe?

How much do you pay for the servers that run actions? Is it much more than $610? Then it kinda makes sense.

IMO it's long time coming. Streaming logs and other supporting functionality is not free. We at Cirrus Runners provide runners as a service for a fixed monthly price with unlimited usage. We target large entrerprises that save $100K+ yearly by switching to us (10-25 times). In our calculations the new per-minute fee is roughly ~0.1% of the effective per-minute cost our customers avoid by using our fixed-price model. Over providers with the traditional per-minute pricing will have bigger impact.

Today GitHub announced changes to pricing for GitHub-managed runners and introduced a new per-minute charge for organizations using self-hosted runners. Below we’ll dive into what changed, the backstory, how companies have been using self-hosted runners, and how this affects third-party providers like Cirrus Runners.

Cirrus Runners being doing it for a long time now:

https://cirrus-runners.app/

There’s been a lot of conversations about moving off the traditional cloud for companies to save tremendously on infrastructure bills. Famously DHH and 37signals moved off AWS to their own hardware to save millions.

We are doing something similar with Cirrus Runners...

Cirrus Runners team controls, develops and optimizes every layer of the infrastructure involved, from provisioning the fastest bare-metal servers off traditional clouds to building state of the art virtualization solutions for macOS called Tart and for Linux called Vetu.

This vertical integration allows us to provide the most cost-efficient infrastructure for your GitHub Actions. Unlimited monthly usage for a fixed price. No hidden fees. No surprises.

Please check out and comment on this issue. There is some movement around but primary it’s waiting for the new promised Vagrant version in Go.

https://github.com/hashicorp/vagrant/issues/12760

Initially there were a lot of interest from Anka users to migrate to a more scalable and DX friendly tool. That’s why FAQ started with comparison. In a nutshell these tools are similar but taking different approaches for the same problems: OCI registries vs own implementation, CLI first vs REST oriented, Packer/VNC vs own scripting, etc.

You can setup a Linux dev VM but unfortunately it won’t have access to the GPU. There is Rosetta 2 support though which works brilliantly with amd64 binaries.

Realization for the license change was a bit different. From day 1 we knew Tart is good and hoped to build a healthy ecosystem around it. Unfortunately, our enthusiasm wasn't met by big companies. You can check this blog post for more details https://tart.run/blog/2023/02/11/changing-tart-license/.

The free usage is pretty generous: free on any amount of personal computers including personal workstations and up to 100 cores (12 Mac Minis) when installed on servers. If your organizations needs a bigger installation then it's probably values the product and can budget out a little bit to support it.

macOS EULA has some special wording around "Permitted Developer Services" allowing more flexibility:

> Permitted Developer Services means continuous integration services, including but not limited to software development, building software from source, automated testing during software development, and running necessary developer tools to support such activities.

As for layering, Tart doesn't support it at the moment. It seems APFS is not particularly good for layering but Tart uses sparsed files when storing VMs locally. Sparsed disk image file basically "skips" zero bytes which saves a lot.

Also want to note availability of GitLab Executor, Buildkite plugin and many more integrations for all kinds of workflows.

There is a paravirtualized GPU available to macOS hosts. But it’s a bit limited and might not work for LLMs but worth trying since it might work.

Cirrus Runners has a fixed monthly price with unlimited minutes usage.

There are Cirrus Runners which is a service of managed GitHub Actions Runners powered by M2 chips. But there is no free option for OSS yet. https://tart.run/integrations/github-actions

Cirrus Runners which had only 4CPUs / 12GB configuration introduced XL runners with twice the resources.

Orchard is a new orchestrator to manage macOS Virtual Machines at scale. This post covers the motivation behind creating yet another orchestrator and why Kubernetes or Nomad was not an option.

Not at the moment. For the initial release we focused on macOS but the Virtualization.Framework supports Linux. I've created a feature request. Feel free to comment with your use case for Linux. https://github.com/cirruslabs/tart/issues/62

Unfortunately, macOS itself is pretty heavy and takes up 20ish GB itself. Tart can work with smaller VM sizes but it's hard to create one.

On a bright size Tart compresses the disk layers and you'll only need to download about 18 GB over the internet.

Tart is a virtualization toolset to build, run and manage macOS virtual machines on Apple Silicon.

One of the most interesting/unique features is the integration with OCI-compatible container registries. Tart can pull/push virtual machines from/to a registry. This feature was inspired by OCI Artifacts initiative.