He's a billionaire, has sponsors and has a startup.

Huh, I was told billionaires are evil.

"Mitchell Hashimoto is a software developer and entrepreneur best known as the co-founder of HashiCorp, which was acquired by IBM for $6.4 billion in 2025."

Many common ways for the financing of an free and open source project to be sustainable (The main keyword) in the mid to long term:

1) A non-profit company that has full-time employees but supported via sponsorships. (gnu project, mastodon, omarchy, zig)

2) Multiple for-profit companies that each have full-time employees to contribute to an open source project that they all use. (ocaml, linux, rust)

3) A ultra high net worth individual that has full-time contributors to open source, supported via a non-profit (signal, ghostty)

4) A for-profit company that has dedicated full-time employees that have full support and own the direction of the open source project (go, swift, java)

5) VC funded open source projects (Herdr, Bun, Deno, Burno, Atuin)

All other options such as low donations (GH sponsorships), "buy me a coffee", ko-fi, are completely unsustainable, now that AI agents exist.

It’s really hard to come up with better conditions for an open-source project than what libghostty has. I’m pretty sure it will be the last terminal emulator at this point.

> A for-profit company that has dedicated full-time employees that have full support and own the direction of the open source project (go, swift, java)

I think this has not been the case for Java in quite a while. It is a community project now.

Yes and no. It is a community project, but a lot of the leadership are Oracle employees.

you missed the 99% case, which is some random person who has a reasonably well paying day job and develops the project in their spare time. AI agents make that more sustainable, not less. vim is a good example, as are a lot of popular programming languages.

That's not sustainable. If $DAYJOB becomes too busy the project will stall because the random person won't have enough time to work on it anymore.

it's not sustainable in theory, because you can definitely think up valid failure modes like that. in practice though it's how a huge percentage of open source software out there is developed and maintained. at most the bdfl becomes less active in development but continues to shepherd the project as it attracts other contributors.

He has billionaire investors. Probably the only grey note about his ventures here.

He posted here a while back, paraphrased "My revenue model is my bank account has 10 digits". He's wealthy and likes to code and is giving back to the community